Effects of Hyperoxia on Type II Cell Surfactant Synthesis

2015 ◽  
pp. 291-293
Author(s):  
B. A. Holm ◽  
S. Matalon
Keyword(s):  
Type Ii ◽  
Surfactant Synthesis ◽  
Type Ii Cell

Inhibition of alveolar type II cell ATP and surfactant synthesis by nitric oxide

1996 ◽  
Vol 270 (6) ◽  
pp. L898-L906 ◽  
Author(s):  
I. Y. Haddad ◽  
S. Zhu ◽  
J. Crow ◽  
E. Barefield ◽  
T. Gadilhe ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Lipid Synthesis ◽  
Alveolar Epithelium ◽  
Alveolar Type ◽  
Type Ii ◽  
Surfactant Synthesis ◽  
Cell Energy ◽  
Type Ii Cell

Alveolar type II (ATII) cells, are often exposed to increased concentration of endogenous and exogenous nitric oxide (.NO). Exposure of freshly isolated rat ATII cells for 2 h to 1-3 microM .NO, generated by S-nitroso-N-penicillamine (SNAP), spermine NONOate, or 3-morpholino-sydnonimine (SIN-1) in the presence of superoxide dismutase, resulted in approximately 60% decrease in the rate of surfactant synthesis, as measured by the rate of incorporation of [methyl-3H]choline into phosphatidylcholine, and 60-80% inhibition of cellular ATP levels, as determined by bioluminescence. Similar results were obtained after incubation of ATII cells with authentic peroxynitrite (0.5 mM) but not SIN-1, a putative generator of peroxynitrite. Addition into the medium of oxyhemoglobin (20 microM), which scavenged .NO, or enhancement of ATII glutathione levels by preincubation with glutathione ester (5 mM) totally prevented the NONOate (100 microM) inhibition of cellular ATP. In contrast to the in vitro findings, normal levels of ATP and lipid synthesis were measured in ATII cells isolated from the lungs of rats that breathed .NO gas (80 ppm) in 21% O2 for 2 h (n = 4). This lack of effect may be due either to the presence of various antioxidants (such as glutathione) in the epithelial lining fluid or to the relatively low concentrations of .NO reaching the alveolar epithelium. We conclude that .NO and peroxynitrite, at concentrations likely to be encountered in vivo during inflammation, decrease ATII cell energy stores and surfactant synthesis, which may lead to derangement of important physiological functions.

Androgen Inhibits TACE-Mediated Components Of Fetal Type II Cell Surfactant Synthesis

2010 ◽  
Author(s):  
Lucia D. Pham ◽  
Sana Mujahid ◽  
Sandy L. Murray ◽  
MaryAnn V. Volpe ◽  
Heber C. Nielsen
Keyword(s):  
Type Ii ◽  
Surfactant Synthesis ◽  
Type Ii Cell

Halothane Potentiation of Hydrogen Peroxide-Induced Inhibition of Surfactant Synthesis: The Role of Type II Cell Energy Status

2002 ◽  
Vol 94 (4) ◽  
pp. 943-947 ◽  
Author(s):  
Alka B. Patel ◽  
June Sokolowski ◽  
Bruce A. Davidson ◽  
Paul R. Knight ◽  
Bruce A. Holm
Keyword(s):  
Hydrogen Peroxide ◽  
Type Ii ◽  
Energy Status ◽  
Surfactant Synthesis ◽  
Cell Energy ◽  
Type Ii Cell

scholarly journals Covid-19 Interstitial Pneumonia: Histological and Immunohistochemical Features on Cryobiopsies

Respiration ◽  
2021 ◽  
pp. 369-379
Author(s):  
Claudio Doglioni ◽  
Claudia Ravaglia ◽  
Marco Chilosi ◽  
Giulio Rossi ◽  
Alessandra Dubini ◽  
...  
Keyword(s):  
Interstitial Pneumonia ◽  
Diffuse Alveolar Damage ◽  
Alveolar Type ◽  
Type Ii ◽  
Cell Hyperplasia ◽  
Nuclear Expression ◽  
Alveolar Type Ii Cell ◽  
Hyaline Membranes ◽  
Type Ii Cell ◽  
Phosphorylated Stat3

Background: The pathogenetic steps leading to Covid-19 interstitial pneumonia remain to be clarified. Most postmortem studies to date reveal diffuse alveolar damage as the most relevant histologic pattern. Antemortem lung biopsy may however provide more precise data regarding the earlier stages of the disease, providing a basis for novel treatment approaches. Objectives: To ascertain the morphological and immunohistochemical features of lung samples obtained in patients with moderate Covid-19 pneumonia. Methods: Transbronchial lung cryobiopsy was carried out in 12 Covid-19 patients within 20 days of symptom onset. Results: Histopathologic changes included spots of patchy acute lung injury with alveolar type II cell hyperplasia, with no evidence of hyaline membranes. Strong nuclear expression of phosphorylated STAT3 was observed in >50% of AECII. Interalveolar capillaries showed enlarged lumen and were in part arranged in superposed rows. Pulmonary venules were characterized by luminal enlargement, thickened walls, and perivascular CD4+ T-cell infiltration. A strong nuclear expression of phosphorylated STAT3, associated with PD-L1 and IDO expression, was observed in endothelial cells of venules and interstitial capillaries. Alveolar spaces macrophages exhibited a peculiar phenotype (CD68, CD11c, CD14, CD205, CD206, CD123/IL3AR, and PD-L1). Conclusions: Morphologically distinct features were identified in early stages of Covid-19 pneumonia, with epithelial and endothelial cell abnormalities different from either classical interstitial lung diseases or diffuse alveolar damage. Alveolar type II cell hyperplasia was a prominent event in the majority of cases. Inflammatory cells expressed peculiar phenotypes. No evidence of hyaline membranes and endothelial changes characterized by IDO expression might in part explain the compliance and the characteristic pulmonary vasoplegia observed in less-advanced Covid-19 pneumonia.

Regulation of extracellular matrix synthesis by TNF-α and TGF-β1 in type II cells exposed to coal dust

1998 ◽  
Vol 275 (4) ◽  
pp. L637-L644 ◽  
Author(s):  
Yu-Chen Lee ◽  
D. Eugene Rannels
Keyword(s):  
Extracellular Matrix ◽  
Cell Cultures ◽  
Transforming Growth Factor ◽  
Coal Dust ◽  
Transforming Growth Factor Β1 ◽  
Type Ii ◽  
Tnf Α ◽  
Type Ii Cell ◽  
Primary Type ◽  
Tgf Β1

Type II pulmonary epithelial cells respond to anthracite coal dust PSOC 867 with increased synthesis of extracellular matrix (ECM) components. Alveolar macrophages modulate this response by pathways that may involve soluble mediators, including tumor necrosis factor-α (TNF-α) or transforming growth factor-β1 (TGF-β1). The effects of TNF-α (10 ng/ml) and/or TGF-β1 (2 ng/ml) were thus investigated in dust-exposed primary type II cell cultures. In control day 1 or day 3 cultures, TNF-α and/or TGF-β1 had little or no effect on the synthesis of type II cellular proteins, independent of whether the cells were exposed to dust. With PSOC 867 exposure, where ECM protein synthesis is elevated, TNF-α and TGF-β1 further increased both the absolute and relative rates of ECM synthesis on day 3 but had little effect on day 1. Each mediator increased expression of fibronectin mRNA, as well as of ECM fibronectin content, in a manner qualitatively similar to their effects on synthesis. Thus TNF-α and TGF-β1 modulate both ECM synthesis and fibronectin content in coal dust-exposed type II cell cultures.

P2u purinoceptor stimulation of surfactant secretion coupled to phosphatidylcholine hydrolysis in type II cells

1994 ◽  
Vol 267 (5) ◽  
pp. L625-L633 ◽  
Author(s):  
L. I. Gobran ◽  
Z. X. Xu ◽  
Z. Lu ◽  
S. A. Rooney
Keyword(s):  
Phospholipase D ◽  
Receptor Gene ◽  
Primary Cultures ◽  
Cell Receptor ◽  
Northern Analysis ◽  
Type Ii Cells ◽  
Type Ii ◽  
Type Ii Cell ◽  
Subsequent Activation ◽  
Phosphatidylcholine Secretion

ATP is known to stimulate surfactant phospholipid secretion in type II cells, and there is evidence that this effect is mediated by a P2 purinoceptor. At least five subtypes of the P2 receptor have been reported, but it is not clear which one exists on the type II cell. To determine whether it is the P2u subtype, at which UTP is equipotent with ATP, we have compared the effects of ATP and UTP on phosphatidylcholine secretion and second messenger formation in primary cultures of rat type II cells. ATP and UTP were equally potent in stimulating phosphatidylcholine secretion and phospholipase D activation. The potency order, UTP = ATP > ADP > 2-methylthio-ATP, was the same as that reported for the P2u receptor. UTP stimulated diacylglycerol and phosphatidic acid formation to the same extent as ATP. ATP also increased choline formation. Formation of diacylglycerol was biphasic, and the first peak in response to ATP was previously shown to be associated with inositol trisphosphate formation. Northern analysis showed that the P2u receptor gene was expressed to a greater extent in type II cells than in whole lung. These data suggest that ATP and UTP act via a P2u receptor that is coupled to phosphoinositide-specific phospholipase C with subsequent activation of phospholipase D acting on phosphatidylcholine. ATP has also been reported to act at an additional type II cell receptor coupled to adenylate cyclase. In contrast, UTP did not promote adenosine 3',5'-cyclic monophosphate formation and therefore does not act at that receptor.

Connexin expression by alveolar epithelial cells is regulated by extracellular matrix

2001 ◽  
Vol 280 (2) ◽  
pp. L191-L202 ◽  
Author(s):  
Yihe Guo ◽  
Cara Martinez-Williams ◽  
Clare E. Yellowley ◽  
Henry J. Donahue ◽  
D. Eugene Rannels
Keyword(s):  
Extracellular Matrix ◽  
Epithelial Cells ◽  
Gap Junction ◽  
Intercellular Communication ◽  
Translational Regulation ◽  
Alveolar Epithelial Cells ◽  
Alveolar Type ◽  
Type Ii ◽  
Gap Junction Intercellular Communication ◽  
Type Ii Cell

Extracellular matrix (ECM) proteins promote attachment, spreading, and differentiation of cultured alveolar type II epithelial cells. The present studies address the hypothesis that the ECM also regulates expression and function of gap junction proteins, connexins, in this cell population. Expression of cellular fibronectin and connexin (Cx) 43 increase in parallel during early type II cell culture as Cx26 expression declines. Gap junction intercellular communication is established over the same interval. Cells plated on a preformed, type II cell-derived, fibronectin-rich ECM demonstrate accelerated formation of gap junction plaques and elevated gap junction intercellular communication. These effects are blocked by antibodies against fibronectin, which cause redistribution of Cx43 protein from the plasma membrane to the cytoplasm. Conversely, cells cultured on a laminin-rich ECM, Matrigel, express low levels of Cx43 but high levels of Cx26, reflecting both transcriptional and translational regulation. Cx26 and Cx43 thus demonstrate reciprocal regulation by ECM constituents.

scholarly journals Spectral Monitoring of Surfactant Clearance during Alveolar Epithelial Type II Cell Differentiation

2008 ◽  
Vol 95 (12) ◽  
pp. 5978-5987 ◽  
Author(s):  
Robin J. Swain ◽  
Sarah J. Kemp ◽  
Peter Goldstraw ◽  
Teresa D. Tetley ◽  
Molly M. Stevens
Keyword(s):  
Cell Differentiation ◽  
Type Ii ◽  
Alveolar Epithelial ◽  
Type Ii Cell ◽  
Spectral Monitoring
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