GM-CSF enhances lung growth and causes alveolar type II epithelial cell hyperplasia in transgenic mice

1997 ◽  
Vol 273 (4) ◽  
pp. L715-L725 ◽  
Author(s):  
Jacquelyn A. Huffman Reed ◽  
Ward R. Rice ◽  
Zsuzsanna K. Zsengellér ◽  
Susan E. Wert ◽  
Glenn Dranoff ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Transgenic Mice ◽  
Lung Epithelial Cells ◽  
Alveolar Type ◽  
Type Ii Cells ◽  
Type Ii ◽  
Cell Hyperplasia ◽  
Α Subunit ◽  
Gm Csf ◽  
Type Ii Cell

The human surfactant protein (SP)-C gene promoter was used to direct expression of mouse granulocyte macrophage colony-stimulating factor (GM-CSF; SP-C-GM mice) in lung epithelial cells in GM-CSF-replete (GM+/+) or GM-CSF null mutant (GM−/−) mice. Lung weight and volume were significantly increased in SP-C-GM mice compared with GM+/+ or GM−/− control mice. Immunohistochemical staining demonstrated marked type II cell hyperplasia, and immunofluorescent labeling for proliferating cell nuclear antigen was increased in type II cells of SP-C-GM mice. Abundance of type II cells per mouse lung was increased three- to fourfold in SP-C-GM mice compared with GM+/+ and GM−/− mice. GM-CSF increased bromodeoxyuridine labeling of isolated type II cells in vitro. Type II cells, alveolar macrophages, and endothelial and bronchiolar epithelial cells were stained by antibodies to the GM-CSF receptor α-subunit in both GM+/+ mice and GM-CSF gene-targeted mice that are also homozygous for the SP-C-GM transgene. High levels of GM-CSF expression in type II cells of transgenic mice increased lung size and caused type II cell hyperplasia, demonstrating an unexpected role for the molecule in the regulation of type II cell proliferation and differentiation.

Secretion of cytokines by rat alveolar epithelial cells: possible regulatory role for SP-A

1994 ◽  
Vol 266 (2) ◽  
pp. L148-L155 ◽  
Author(s):  
H. Blau ◽  
S. Riklis ◽  
V. Kravtsov ◽  
M. Kalina
Keyword(s):  
Epithelial Cells ◽  
Alveolar Epithelial Cells ◽  
Alveolar Type ◽  
Type Ii Cells ◽  
Type Ii ◽  
Alveolar Type Ii Cells ◽  
Long Term Culture ◽  
Alveolar Epithelial ◽  
Gm Csf

Cultured alveolar type II cells and pulmonary epithelial (PE) cells in long-term culture were found to secrete colony-stimulating factors (CSF) into the medium in similar fashion to alveolar macrophages. CSF activity was determined by using the in vitro assay for myeloid progenitor cells [colony-forming units in culture (CFU-C)]. Both lipopolisaccharide (LPS) and interleukin-1 alpha (IL-1 alpha) were found to upregulate the secretion 6.5- to 8-fold from alveolar type II cells and macrophages. However, no stimulatory effect of these factors was observed in PE cells that release CSF into the medium constitutively, possibly due to the conditions of long-term culture. The CSF activity was partially neutralized (70% inhibition) by antibodies against murine granulocyte/macrophage (GM)-CSF and IL-3, thus indicating the presence of both GM-CSF and IL-3-like factors in the CSF. However, the presence of other cytokines in the CSF is highly probable. Surfactant-associated protein A (SP-A), which is known to play a central role in surfactant homeostasis and function, was also found to upregulate secretion of CSF (at concentrations of 0.1-5 micrograms/ml) from alveolar type II cells and macrophages. Control cells such as rat peritoneal macrophages, alveolar fibroblasts, and 3T3/NIH cell line could not be elicited by SP-A to release CSF. The results are discussed in relation to the possible participation of the alveolar epithelial cells in various intercellular signaling networks. Our studies suggest that alveolar type II cells and SP-A may play an important regulatory role in the modulation of immune and inflammatory effector cells within the alveolar space.

A noninducible cystine transport system in rat alveolar type II cells

1995 ◽  
Vol 268 (1) ◽  
pp. L21-L26 ◽  
Author(s):  
D. M. Bukowski ◽  
S. M. Deneke ◽  
R. A. Lawrence ◽  
S. G. Jenkinson
Keyword(s):  
Transport System ◽  
Cell Types ◽  
Lung Epithelial Cells ◽  
Alveolar Type ◽  
Type Ii Cells ◽  
Type Ii ◽  
Lung Epithelial ◽  
Sodium Dependent ◽  
Type Ii Cell ◽  
Rate Limiting

Type II lung epithelial cells are different from other lung cell types in their means of processing and regulating intracellular glutathione (GSH) levels. In lung cell types, including endothelial cells, fibroblasts, smooth muscle cells, and macrophages, oxidants, sulfhydryl reagents, and electrophilic agents have been shown to induce cystine uptake and concomitantly increase GSH levels, suggesting that cysteine, formed by intracellular reduction of cystine, is a rate-limiting substrate for GSH synthesis. The cystine transport increase was reportedly due to increase in activity of a sodium-independent transport system designated xc-. We have now examined cultures of rat lung type II cells exposed to diethylmaleic acid and arsenite. Although a rise in cellular GSH occurred, cystine transport was not induced. Cystine transport in type II cells was found to differ from the xc- system previously described. Type II cell cystine transport is primarily sodium dependent and is inhibitable by aspartate as well as glutamate and homocysteate. We conclude that the type II cell differs from other lung cell types in both its cystine transport mechanism and method of GSH regulation.

GM-CSF mediates alveolar epithelial type II cell changes, but not emphysema-like pathology, in SP-D-deficient mice

2004 ◽  
Vol 287 (6) ◽  
pp. L1333-L1341 ◽  
Author(s):  
Matthias Ochs ◽  
Lars Knudsen ◽  
Lennell Allen ◽  
Amber Stumbaugh ◽  
Stacey Levitt ◽  
...  
Keyword(s):  
Knockout Mice ◽  
Immune Response Gene ◽  
Surfactant Protein D ◽  
Type Ii Cells ◽  
Type Ii ◽  
Cell Hyperplasia ◽  
Alveolar Epithelial ◽  
Gm Csf ◽  
Type Ii Cell ◽  
Deficient Mice

Surfactant protein D (SP-D) is a member of the collectin subfamily of C-type lectins, pattern recognition proteins participating in the innate immune response. Gene-targeted mice deficient in SP-D develop abnormalities in surfactant homeostasis, hyperplasia of alveolar epithelial type II cells, and emphysema-like pathology. Granulocyte/macrophage colony-stimulating factor (GM-CSF) is required for terminal differentiation and subsequent activation of alveolar macrophages, including the expression of matrix metalloproteinases and reactive oxygen species, factors thought to contribute to lung remodeling. Type II cells also express the GM-CSF receptor. Thus we hypothesized GM-CSF might mediate some or all of the cellular and structural abnormalities in the lungs of SP-D-deficient mice. To test this, SP-D (D−G+) and GM-CSF (D+G−) single knockout mice as well as double knockout mice deficient for both SP-D and GM-CSF (D−G−) were analyzed by design-based stereology. Compared with wild type, D−G+ as well as D+G− mice showed decreased alveolar numbers, increased alveolar sizes, and decreased alveolar epithelial surface areas. These emphysema-like changes were present to a greater extent in D−G− mice. D−G+ mice developed type II cell hyperplasia and hypertrophy with increased intracellular surfactant pools, whereas D+G− mice had smaller type II cells with decreased intracellular surfactant pools. In contrast to the emphysematous changes, the type II cell alterations were mostly corrected in D−G− mice. These results indicate that GM-CSF-dependent macrophage activity is not necessary for emphysema development in SP-D-deficient mice, but that type II cell metabolism and proliferation are, either directly or indirectly, regulated by GM-CSF in this model.

scholarly journals The MicroRNA 29 Family Promotes Type II Cell Differentiation in Developing Lung

2016 ◽  
Vol 36 (16) ◽  
pp. 2141-2141 ◽  
Author(s):  
Wei Guo ◽  
Houda Benlhabib ◽  
Carole R. Mendelson
Keyword(s):  
Cell Differentiation ◽  
Epithelial Cells ◽  
Transforming Growth Factor ◽  
Fetal Lung ◽  
Transforming Growth Factor Β ◽  
Late Gestation ◽  
Alveolar Type ◽  
Type Ii Cells ◽  
Type Ii ◽  
Type Ii Cell

Lung alveolar type II cells uniquely synthesize surfactant, a developmentally regulated lipoprotein that is essential for breathing. Expression of the gene (SFTPA) encoding the major surfactant protein, SP-A, in midgestation human fetal lung (HFL) is dramatically induced by cyclic AMP (cAMP). cAMP induction of SP-A expression is repressed by transforming growth factor β (TGF-β) and by hypoxia. In this study, we found that expression of the microRNA 29 (miR-29) family was significantly upregulated in epithelial cells isolated from mouse fetal lung during late gestation and in epithelial cells isolated from HFL explants during type II cell differentiation in culture. miR-29 expression in cultured HFL epithelial cells was increased by cAMP and inhibited by hypoxia, whereas the miR-29 target, TGF-β2, was coordinately decreased. Knockdown of the miR-29 family in cultured HFL type II cells blocked cAMP-induced SP-A expression and accumulation of surfactant-containing lamellar bodies, suggesting their physiological relevance. This occurred through derepression of TGF-β signaling. Notably, cAMP increased binding of endogenous thyroid transcription factor 1 (TTF-1/Nkx2.1) to themiR-29ab1promoter in HFL type II cells, and TTF-1 increasedmiR-29ab1promoter-driven luciferase activity in cotransfection assays. Together, these findings identify miR-29 family members as TTF-1-driven mediators of SP-A expression and type II cell differentiation through repression of TGF-β signaling.

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.

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.

Fluid transport across cultured rat alveolar epithelial cells: a novel in vitro system

2004 ◽  
Vol 287 (1) ◽  
pp. L104-L110 ◽  
Author(s):  
Xiaohui Fang ◽  
Yuanlin Song ◽  
Rachel Zemans ◽  
Jan Hirsch ◽  
Michael A. Matthay
Keyword(s):  
Epithelial Cells ◽  
Fluid Transport ◽  
Alveolar Epithelial Cells ◽  
Lung Epithelial Cells ◽  
Morphological Evidence ◽  
Alveolar Type ◽  
Type Ii ◽  
In Vitro System ◽  
Alveolar Epithelial

Previous studies have used fluid-instilled lungs to measure net alveolar fluid transport in intact animal and human lungs. However, intact lung studies have two limitations: the contribution of different distal lung epithelial cells cannot be studied separately, and the surface area for fluid absorption can only be approximated. Therefore, we developed a method to measure net vectorial fluid transport in cultured rat alveolar type II cells using an air-liquid interface. The cells were seeded on 0.4-μm microporous inserts in a Transwell system. At 96 h, the transmembrane electrical resistance reached a peak level (1,530 ± 115 Ω·cm2) with morphological evidence of tight junctions. We measured net fluid transport by placing 150 μl of culture medium containing 0.5 μCi of 131I-albumin on the apical side of the polarized cells. Protein permeability across the cell monolayer, as measured by labeled albumin, was 1.17 ± 0.34% over 24 h. The change in concentration of 131I-albumin in the apical fluid was used to determine the net fluid transported across the monolayer over 12 and 24 h. The net basal fluid transport was 0.84 μl·cm−2·h−1. cAMP stimulation with forskolin and IBMX increased fluid transport by 96%. Amiloride inhibited both the basal and stimulated fluid transport. Ouabain inhibited basal fluid transport by 93%. The cultured cells retained alveolar type II-like features based on morphologic studies, including ultrastructural imaging. In conclusion, this novel in vitro system can be used to measure net vectorial fluid transport across cultured, polarized alveolar epithelial cells.

Sulfation of extracellular matrices modifies responses of alveolar type II cells to fibroblast growth factors

1996 ◽  
Vol 271 (5) ◽  
pp. L688-L697 ◽  
Author(s):  
P. L. Sannes ◽  
J. Khosla ◽  
P. W. Cheng
Keyword(s):  
Growth Factors ◽  
Biological Significance ◽  
Alveolar Type ◽  
Type I ◽  
Type Ii Cells ◽  
Type Ii ◽  
Fibroblast Growth ◽  
Alveolar Type Ii Cells ◽  
Proliferation And Differentiation ◽  
Type Ii Cell

The pulmonary alveolar basement membrane (BM) associated with alveolar type II cells has been shown to be significantly less sulfated than that of type I cells. To examine the biological significance of this observation, we measured the incorporation of 5-bromodeoxyuridine (BrdU) as an indicator of DNA synthesis in isolated rat type II cells cultured for 72-120 h on substrata that were naturally sulfated, not sulfated, or chemically desulfated in serum-free, hormonally defined media, with and without selected growth factors. The percentage of cells incorporating BrdU was significantly elevated by desulfated chondroitin sulfate in the presence of fibroblast growth factor-2 (FGF-2 or basic FGF) and depressed by heparin in the presence of either FGF-1 or acidic FGF or FGF-2. This depressive effect was lost by removing sulfate from the heparin. Some responses were dependent on the period of time in culture and concentration and molecular weight of the substrata. These observations support the notion that sulfation per se of certain components of BM is a key determinant of type II cell responses to select growth factors that may define patterns of proliferation and differentiation.

A human SP-C promoter fragment targets α1-proteinase inhibitor gene expression to lung alveolar type II cells in transgenic mice

1996 ◽  
Vol 5 (2) ◽  
pp. 139-143 ◽  
Author(s):  
Eric Degryse ◽  
Maria M. De Santi ◽  
Mireille Dietrich ◽  
Dalila Ali Hadji ◽  
Jean François Spetz ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transgenic Mice ◽  
Proteinase Inhibitor ◽  
Alveolar Type ◽  
Type Ii Cells ◽  
Type Ii ◽  
Alveolar Type Ii Cells ◽  
Promoter Fragment ◽  
Inhibitor Gene

Nitric oxide alters metabolism in isolated alveolar type II cells

1996 ◽  
Vol 271 (1) ◽  
pp. L23-L30 ◽  
Author(s):  
P. R. Miles ◽  
L. Bowman ◽  
L. Huffman
Keyword(s):  
Nitric Oxide ◽  
Oxygen Consumption ◽  
Atp Synthesis ◽  
Alveolar Type ◽  
Type Ii Cells ◽  
Type Ii ◽  
Atp Content ◽  
Alveolar Type Ii Cells ◽  
Type Ii Cell ◽  
Cellular Oxygen

Alveolar type II cells may be exposed to nitric oxide (.NO) from external sources, and these cells can also generate .NO. Therefore we studied the effects of altering .NO levels on various type II cell metabolic processes. Incubation of cells with the .NO generator, S-nitroso-N-acetylpenicillamine (SNAP; 1 mM), leads to reductions of 60-70% in the synthesis of disaturated phosphatidylcholines (DSPC) and cell ATP levels. Cellular oxygen consumption, an indirect measure of cell ATP synthesis, is also reduced by SNAP. There is no direct effect of SNAP on lung mitochondrial ATP synthesis, suggesting that .NO does not directly inhibit this process. On the other hand, incubation of cells with NG-nitro-L-arginine methyl ester (L-NAME), an inhibitor of nitric oxide synthase (NOS), the enzyme responsible for .NO synthesis, results in increases in DSPC synthesis, cell ATP content, and cellular oxygen consumption. The L-NAME effects are reversed by addition of L-arginine, the substrate for NOS. Production of .NO by type II cells is inhibited by L-NAME, a better inhibitor of constitutive NOS (cNOS) than inducible NOS (iNOS), and is reduced in the absence of external calcium. Aminoguanidine, a specific inhibitor of iNOS, has no effect on cell ATP content or on .NO production. These results indicate that alveolar type II cell lipid and energy metabolism can be affected by .NO and suggest that there may be cNOS activity in these cells.

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