scholarly journals Hydrogen sulfide donor NaHS induces death of alveolar epithelial L2 cells that is associated with cellular shrinkage, transgelin expression and myosin phosphorylation

2016 ◽  
Vol 41 (5) ◽  
pp. 645-654 ◽  
Author(s):  
Yusuke Fujii ◽  
Takeshi Funakoshi ◽  
Kana Unuma ◽  
Kanako Noritake ◽  
Toshihiko Aki ◽  
...  
Keyword(s):  
Hydrogen Sulfide ◽  
Myosin Phosphorylation ◽  
Alveolar Epithelial ◽  
L2 Cells ◽  
Cellular Shrinkage

Nitric oxide donors inhibit spontaneous depolarizations by L-type Ca2+ currents in alveolar epithelial cells

1997 ◽  
Vol 272 (6) ◽  
pp. L1092-L1097
Author(s):  
W. Schobersberger ◽  
F. Friedrich ◽  
G. Hoffmann ◽  
H. Volkl ◽  
P. Dietl
Keyword(s):  
Nitric Oxide ◽  
Soluble Guanylyl Cyclase ◽  
Alveolar Epithelial Cells ◽  
Pronounced Increase ◽  
No Donors ◽  
Cyclic Monophosphate ◽  
Alveolar Epithelial ◽  
Voltage Dependent ◽  
Ca2 Channels ◽  
L2 Cells

L2 cells, a cloned pneumocyte-derived cell line, express voltage-dependent L-type Ca2+ channels, causing transient depolarizing spikes of the membrane potential (Vm) [P. Dietl, T. Haller, B. Wirleitner, H. Volkl, F. Friedrich, and J. Striessing. Am. J. Physiol. 269 (Lung Cell. Mol. Physiol. 13): L873-L883, 1995]. In this study, we examined the effect of nitric oxide (NO)- and guanosine 3',5'-cyclic monophosphate (cGMP)-dependent cell signaling on the activity of L-type Ca2+ channels. Using conventional microelectrodes, spontaneous depolarizations (SD) of Vm by activation of these channels are regularly seen in the presence of 10 mM bath Sr2+. The NO donors sodium nitroprusside (SNP; 1 mM), 3-morpholinosydnonimine (SIN-1; 100 microM), as well as S-nitroso-N-acetyl-D,L-penicillamine (SNAP; 10 microM) caused a significant reduction of the frequency of Sr(2+)-induced SD. These effects were completely reversed by 6-anilino-5,8-quinolinequinone (10 microM), an inhibitor of the soluble guanylyl cyclase, and could be mimicked by 8-bromoguanosine 3'5'-cyclic monophosphate (8-BrcGMP; 100 microM). Perforated patch-clamp experiments revealed that 8-BrcGMP exerted a significant decrease of the depolarization-induced L-type Sr2+ current in the majority of tested cells. Consistent with the dependency of these NO-mediated effects on cGMP, incubation of L2 cells with SNP, SIN-1, and SNAP lead to a pronounced increase of cellular cGMP concentration. We conclude that the NO donors inhibit the activity of L-type Ca2+ channels in L2 cells via a cGMP-dependent pathway. In the alveoli, this might occur under conditions associated with the release of NO.

Contrasting effects of alveolar macrophages and neutrophils on asbestos-induced pulmonary epithelial cell injury

1994 ◽  
Vol 266 (1) ◽  
pp. L84-L91 ◽  
Author(s):  
D. W. Kamp ◽  
M. M. Dunn ◽  
J. S. Sbalchiero ◽  
A. M. Knap ◽  
S. A. Weitzman
Keyword(s):  
Epithelial Cell ◽  
Incubation Period ◽  
Alveolar Macrophages ◽  
Cell Injury ◽  
Alveolar Epithelial Cell ◽  
Alveolar Epithelial Cells ◽  
51Cr Release ◽  
Alveolar Epithelial ◽  
L2 Cells ◽  
Epithelial Cell Injury

Pulmonary toxicity from asbestos may be due in part to oxidant-mediated mechanisms. The purpose of this study was to determine whether alveolar macrophages (AM) contribute to asbestos-induced alveolar epithelial cell injury by oxidant-dependent mechanisms similar to that previously described for polymorphonuclear leukocytes (PMN). We assessed 51Cr release from cultured rat alveolar epithelial cells (RAEC) and transformed human pulmonary epithelial-like cell lines (rat L2 and human WI-26: HPEC). Amosite asbestos caused dose-dependent injury to both RAEC and L2 cells after an 18-h incubation period. Rat PMN increased asbestos-induced injury to RAEC (11 vs. 20% 51Cr release). In contrast, rat AM diminished asbestos-induced injury to RAEC and L2 cells by 60-80%. Human monocytes cultured for 72 h also attenuated asbestos-induced HPEC damage. Asbestos stimulated more H2O2 release from PMN than from AM isolated from the same rats (5.3 +/- 0.6 vs. 0.3 +/- 0.1 nmol x 10(6) cells-1 x 2h-1). The protective effect of rat AM, as opposed to PMN, was not due to differences in asbestos-induced toxicity to each cell type, since > 90% of AM and PMN were nonviable after 18 h. Transmission electron microscopy demonstrated comparable uptake of asbestos by AM and PMN after a 2-h incubation period. However, after an 18-h exposure period, the PMN were completely lysed, whereas over 90% of the AM contained fibers, despite morphologic evidence of cytotoxicity. These results demonstrate that AM, unlike PMN, can reduce alveolar epithelial cell injury in this model.(ABSTRACT TRUNCATED AT 250 WORDS)

Endothelin-1 synthesis, receptors, and signal transduction in alveolar epithelium: evidence for an autocrine role

1995 ◽  
Vol 268 (2) ◽  
pp. L192-L200 ◽  
Author(s):  
B. A. Markewitz ◽  
D. E. Kohan ◽  
J. R. Michael
Keyword(s):  
Signal Transduction ◽  
Growth Factor ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Alveolar Epithelial Cell ◽  
Alveolar Epithelial Cells ◽  
Pge2 Production ◽  
Endothelin 1 ◽  
Alveolar Epithelial ◽  
L2 Cells

In the lung, endothelin-1 (ET-1) is synthesized by several cell types and acts locally to cause vasoconstriction and bronchoconstriction, activate alveolar macrophages, and stimulate chloride secretion. We report ET-1 production, binding, and signal transduction by a previously unrecognized site, the alveolar epithelial cell. L2 cells, a cloned rat alveolar epithelial cell line, secreted ET-1 and contained ET-1 mRNA. Exposure of L2 cells to lipopolysaccharide, tumor necrosis factor-alpha, interleukin-1, or transforming growth factor-beta stimulated ET-1 release, whereas interferon-gamma or platelet-derived growth factor decreased ET-1 secretion. 125I-ET-1 binding to L2 cells revealed a single binding site with a maximal binding capacity of 22.4 fmol/mg protein and a dissociation constant of 4.03 nM. 125I-ET-1 binding was completely inhibited by ET receptor A (ETA) blockade and by unlabeled ET-1 >> ET-3 = sarafotoxin 6c, consistent with the presence of ETA. Exogenous ET-1 increased, whereas blockade of endogenous ET-1 decreased prostaglandin E2 (PGE2) production by L2 cells; exogenous ET-1 also increased adenosine 3',5'-cyclic monophosphate (cAMP) production. We conclude that 1) cloned rat alveolar epithelial cells synthesize ET-1; 2) inflammatory mediators modulate ET-1 production; 3) L2 cells express ETA; 4) ET-1 increases PGE2 and cAMP levels in these cells; and 5) BQ-123, an ETA antagonist, decreases their basal PGE2 production. These studies suggest that ET-1 may function as an autocrine factor in alveolar epithelial cells.

Lipopolysaccharide induces functional ICAM-1 expression in rat alveolar epithelial cells in vitro

2000 ◽  
Vol 278 (3) ◽  
pp. L572-L579 ◽  
Author(s):  
Caveh Madjdpour ◽  
Beat Oertli ◽  
Urs Ziegler ◽  
John M. Bonvini ◽  
Thomas Pasch ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Apical Part ◽  
Alveolar Epithelial Cells ◽  
Intercellular Adhesion Molecule ◽  
Lymphocyte Function ◽  
Intercellular Adhesion Molecule 1 ◽  
Alveolar Epithelial ◽  
A Cell ◽  
L2 Cells

Lipopolysaccharide (LPS)-induced lung inflammation is known to increase pulmonary intercellular adhesion molecule-1 (ICAM-1) expression. In the present study, L2 cells, a cell line of alveolar epithelial cells, were stimulated with LPS, and ICAM-1 expression was studied. ICAM-1 protein on L2 cells peaked at 6 (38% increase; P < 0.01) and 10 (48% increase; P < 0.001) h after stimulation with Escherichia coli and Pseudomonas aeruginosa LPS, respectively. ICAM-1 mRNA expression was markedly increased, with a peak at 2–4 ( E. coli) and 4–6 ( P. aeruginosa) h. Adherence assays of neutrophils to LPS-stimulated L2 cells showed a threefold increase in adherence ( P < 0.001). Pretreatment of the neutrophils with anti-lymphocyte function-associated antigen-1 and anti-Mac-1 antibodies reduced adherence by 54% ( P < 0.001). Analysis of immunofluorescence staining for ICAM-1 showed an exclusive apical expression of ICAM-1. These results indicate that LPS upregulates functional active ICAM-1 on the apical part of the membrane in rat pneumocytes.

Endogenous hydrogen sulfide sulfhydrates IKKβ at cysteine 179 to control pulmonary artery endothelial cell inflammation

2019 ◽  
Vol 133 (20) ◽  
pp. 2045-2059 ◽  
Author(s):  
Da Zhang ◽  
Xiuli Wang ◽  
Siyao Chen ◽  
Selena Chen ◽  
Wen Yu ◽  
...  
Keyword(s):  
Hydrogen Sulfide ◽  
Endothelial Cell ◽  
Pulmonary Artery ◽  
Cell Model ◽  
Site Directed Mutagenesis ◽  
Critical Event ◽  
Hypertensive Rats ◽  
Pulmonary Artery Endothelial Cell

Abstract Background: Pulmonary artery endothelial cell (PAEC) inflammation is a critical event in the development of pulmonary arterial hypertension (PAH). However, the pathogenesis of PAEC inflammation remains unclear. Methods: Purified recombinant human inhibitor of κB kinase subunit β (IKKβ) protein, human PAECs and monocrotaline-induced pulmonary hypertensive rats were employed in the study. Site-directed mutagenesis, gene knockdown or overexpression were conducted to manipulate the expression or activity of a target protein. Results: We showed that hydrogen sulfide (H2S) inhibited IKKβ activation in the cell model of human PAEC inflammation induced by monocrotaline pyrrole-stimulation or knockdown of cystathionine γ-lyase (CSE), an H2S generating enzyme. Mechanistically, H2S was proved to inhibit IKKβ activity directly via sulfhydrating IKKβ at cysteinyl residue 179 (C179) in purified recombinant IKKβ protein in vitro, whereas thiol reductant dithiothreitol (DTT) reversed H2S-induced IKKβ inactivation. Furthermore, to demonstrate the significance of IKKβ sulfhydration by H2S in the development of PAEC inflammation, we mutated C179 to serine (C179S) in IKKβ. In purified IKKβ protein, C179S mutation of IKKβ abolished H2S-induced IKKβ sulfhydration and the subsequent IKKβ inactivation. In human PAECs, C179S mutation of IKKβ blocked H2S-inhibited IKKβ activation and PAEC inflammatory response. In pulmonary hypertensive rats, C179S mutation of IKKβ abolished the inhibitory effect of H2S on IKKβ activation and pulmonary vascular inflammation and remodeling. Conclusion: Collectively, our in vivo and in vitro findings demonstrated, for the first time, that endogenous H2S directly inactivated IKKβ via sulfhydrating IKKβ at Cys179 to inhibit nuclear factor-κB (NF-κB) pathway activation and thereby control PAEC inflammation in PAH.

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