Effects of RSV infection on pulmonary surfactant protein SP-A in cultured human type II cells: contrasting consequences on SP-A mRNA and protein

2005 ◽  
Vol 289 (6) ◽  
pp. L1113-L1122 ◽  
Author(s):  
Joseph L. Alcorn ◽  
James M. Stark ◽  
Constance L. Chiappetta ◽  
Gaye Jenkins ◽  
Giuseppe N. Colasurdo
Keyword(s):  
Gene Expression ◽  
Protein Gene ◽  
Surfactant Protein ◽  
Type Ii Cells ◽  
Protein Homeostasis ◽  
Mrna Levels ◽  
Type Ii ◽  
Human Type ◽  
Rsv Infection ◽  
Type Ii Cell

Respiratory syncytial virus (RSV) is the most important cause of serious lower respiratory illness in infants and children. Surfactant proteins A (SP-A) and D (SP-D) play critical roles in lung defense against RSV infections. Alterations in surfactant protein homeostasis in the lung may result from changes in production, metabolism, or uptake of the protein within the lung. We hypothesized that RSV infection of the type II cell, the primary source of surfactant protein, may alter surfactant protein gene expression. Human type II cells grown in primary culture possess lamellar bodies (a type II cell-specific organelle) and the ability to express surfactant protein mRNA. These cells were infected with RSV (by morphology and antibody binding). Surfactant protein mRNA levels determined by quantitative RT-PCR indicated a marked increase in SP-A mRNA levels (3-fold) 24 h after RSV exposure, whereas SP-D mRNA levels were unaffected. In contrast to mRNA levels, total SP-A protein levels (determined by Western blot analysis) were decreased 40% after RSV infection. The percentage of secreted SP-A was 43% of the total SP-A in the RSV-infected cells, whereas the percentage of secreted SP-A was 61% of the total SP-A in the uninfected cells. These changes in SP-A transcript levels and protein secretion in cultured human cells were recapitulated in RSV-infected mouse lung. Our findings suggest that type II cells are potentially important targets of RSV lower respiratory infection and that alterations in surfactant protein gene expression and SP-A protein homeostasis in the lung may arise via direct effects of RSV.

Nitric oxide decreases surfactant protein gene expression in primary cultures of type II pneumocytes

2005 ◽  
Vol 288 (5) ◽  
pp. L950-L957 ◽  
Author(s):  
Jae W. Lee ◽  
Robert F. Gonzalez ◽  
Cheryl J. Chapin ◽  
Justin Busch ◽  
Jeffrey R. Fineman ◽  
...  
Keyword(s):  
Gene Expression ◽  
Nitric Oxide ◽  
Protein Gene ◽  
Surfactant Protein ◽  
Model Systems ◽  
Cell Phenotype ◽  
Mrna Levels ◽  
Type Ii ◽  
Endothelin 1 ◽  
Type Ii Pneumocytes

Inhaled nitric oxide (NO) is a selective pulmonary vasodilator effective in treating persistent pulmonary hypertension in newborns and in infants following congenital heart disease surgery. Recently, multiple in vivo and in vitro studies have shown a negative effect of NO on surfactant activity as well as surfactant protein gene expression. Although the relationship between NO and surfactant has been studied previously, the data has been hard to interpret due to the model systems used. The objective of the current study was to characterize the effect of NO on surfactant protein gene expression in primary rat type II pneumocytes cultured on a substratum that promoted the maintenance of type II cell phenotype. Exposure to a NO donor, S-nitroso-N-acetylpenicillamine (SNAP), decreased surfactant protein (SP)-A, (SP)-B, and (SP)-C mRNA levels in type II pneumocytes in a time- and dose-dependent manner. The effect was mediated in part by an increase in endothelin-1 secretion and a decrease in the intracellular messenger, phosphorylated ERK1/2 mitogen-activated protein kinases (MAPK). Exposing type II pneumocytes to endothelin-1 receptor antagonists PD-156707 or bosentan before exposure to SNAP partially prevented the decrease in surfactant protein gene expression. The results showed that NO mediated the decrease in surfactant protein gene expression at least in part through an increase in endothelin-1 secretion and a decrease in phosphorylated ERK1/2 MAPKs.

scholarly journals Mechanical Stretch-Activated Type II Cell-Fibroblast Interactions Regulate Surfactant Protein Gene Expression and Alveolar Remodeling

1999 ◽  
Vol 45 (4, Part 2 of 2) ◽  
pp. 319A-319A
Author(s):  
Juan Sanchez-Esteban ◽  
Lawrence Cicchiello ◽  
Shu-Whei Tsai ◽  
Lakisha Y Williams ◽  
Virender K Rehan ◽  
...  
Keyword(s):  
Gene Expression ◽  
Protein Gene ◽  
Mechanical Stretch ◽  
Surfactant Protein ◽  
Type Ii ◽  
Type Ii Cell

Influence of the cytoskeleton on surfactant protein gene expression in cultured rat alveolar type II cells

1998 ◽  
Vol 274 (1) ◽  
pp. L87-L96 ◽  
Author(s):  
John M. Shannon ◽  
Tianli Pan ◽  
Karen E. Edeen ◽  
Larry D. Nielsen
Keyword(s):  
Gene Expression ◽  
Protein Gene ◽  
Primary Cultures ◽  
Surfactant Protein ◽  
Alveolar Type ◽  
Type Ii Cells ◽  
Partial Recovery ◽  
Type Ii ◽  
Alveolar Type Ii Cells

We have investigated the role of the cytoskeleton in surfactant protein gene expression. Cytochalasin D (CD), colchicine (Col), or nocodazole (Noco) were tested on primary cultures of adult rat alveolar type II cells. Treatment with any of the drugs did not result in dramatic cell shape changes, but ultrastructural examination revealed that the cytoplasm of cells treated with CD was markedly disorganized; cells treated with Col did not exhibit such changes. Treatment with any of the three drugs resulted in a reduction in surfactant protein (SP) mRNAs. These decreases were not the result of cell toxicity, since overall protein synthesis was unimpaired by drug treatment. Washing the cells followed by an additional 2 days of culture resulted in a reaccumulation of SP mRNAs in CD-treated cells but not in Col-treated cells. Washing of Noco-treated cultures resulted in partial recovery. SP mRNA stability was estimated in the presence or absence of cytoskeleton-disrupting drugs. Disruption of either microfilaments or microtubules significantly affected the half-lives of mRNAs for SP-A, SP-B, and SP-C. These data support a role for the cytoskeleton in the maintenance of type II cell differentiation and suggest that the role of the cytoskeleton is at least in part to stabilize SP mRNAs.

scholarly journals Heparin and Fibroblast Growth Factors Affect Surfactant Protein Gene Expression in Type II Cells

2006 ◽  
Vol 35 (5) ◽  
pp. 611-618 ◽  
Author(s):  
Kevin A. Leiner ◽  
Donna Newman ◽  
Cheng-Ming Li ◽  
Eric Walsh ◽  
Jody Khosla ◽  
...  
Keyword(s):  
Gene Expression ◽  
Growth Factors ◽  
Protein Gene ◽  
Fibroblast Growth Factors ◽  
Surfactant Protein ◽  
Type Ii Cells ◽  
Type Ii ◽  
Fibroblast Growth

Maintenance of surfactant protein A and D secretion by rat alveolar type II cells in vitro

2002 ◽  
Vol 282 (2) ◽  
pp. L249-L258 ◽  
Author(s):  
Robert J. Mason ◽  
Michele C. Lewis ◽  
Karen E. Edeen ◽  
Kathleen McCormick-Shannon ◽  
Larry D. Nielsen ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Growth Factor ◽  
Surfactant Protein ◽  
Surfactant Proteins ◽  
Type Ii Cells ◽  
Mrna Levels ◽  
Type Ii ◽  
Rat Serum ◽  
Type Ii Cell

Secretion of surfactant proteins A and D (SP-A and SP-D) has been difficult to study in vitro because a culture system for maintaining surfactant secretion has been difficult to establish. We evaluated several growth factors, corticosteroids, rat serum, and a fibroblast feeder layer for the ability to produce and maintain a polarized epithelium of type II cells that secretes SP-A and SP-D into the apical medium. Type II cells were plated on a filter insert coated with an extracellular matrix and were cultured at an air-liquid interface. Keratinocyte growth factor (KGF) stimulated type II cell proliferation and secretion of SP-A and SP-D more than fibroblast growth factor-10 (FGF-10), hepatocyte growth factor (HGF), or heparin-binding epidermal-like growth factor (HB-EGF). Cells cultured in the presence of KGF and rat serum with or without fibroblasts had high surfactant protein mRNA levels and exhibited a high level of SP-A and SP-D secretion. Dexamethasone inhibited type II cell proliferation but increased expression of SP-B. In the presence of KGF, rat serum, and dexamethasone, the mRNAs for the surfactant proteins were maintained at high levels. Secretion of SP-A and SP-D was found to be independent of phospholipid secretion.

Transforming growth factor-beta 1 modulates type II cell fibronectin and surfactant protein C expression

1994 ◽  
Vol 267 (5) ◽  
pp. L569-L577 ◽  
Author(s):  
W. M. Maniscalco ◽  
R. A. Sinkin ◽  
R. H. Watkins ◽  
M. H. Campbell
Keyword(s):  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Surfactant Protein ◽  
Type Ii Cells ◽  
Mrna Levels ◽  
Type Ii ◽  
Tgf Beta ◽  
Surfactant Protein C ◽  
Type Ii Cell ◽  
Growth Factor Beta

Extracellular matrix (ECM) deposition by alveolar type II cells is important for repair of a damaged alveolar epithelium. Transforming growth factor-beta (TGF-beta) is abundant in injured lung and has profound effects on ECM production and cell differentiation. We determined the effects of TGF-beta 1 on type II cell expression of fibronectin and surfactant protein C (SP-C) in vitro. TGF-beta 1 increased the proportion of type II cells with detectable mRNA for fibronectin from 9 to 68%, as demonstrated by in situ hybridization, and increased the fibronectin mRNA levels 10-fold. TGF-beta 1-treated cultures had increased immunostaining for fibronectin and increased secretion of metabolically labeled fibronectin. A decreased proportion of type II cells treated with TGF-beta 1 had detectable mRNA for SP-C, and the abundance of this message per cell decreased to 25% of control values. No effects of TGF-beta 1 were noted on the proportion of cells that contained lamellar bodies, which was 87% in both groups. These data indicate that TGF-beta 1 regulates type II cell fibronectin protein an mRNA levels. In addition, the decreased abundance of SP-C mRNA suggests that TGF-beta 1 may also modulate type II cell differentiation in lung injury.

Early increase in expression of surfactant protein A gene in type II cells from silica-treated rats

1997 ◽  
Vol 273 (2) ◽  
pp. L395-L400
Author(s):  
C. J. Viviano ◽  
S. A. Rooney
Keyword(s):  
Lung Surfactant ◽  
Protein A ◽  
Surfactant Protein ◽  
Type Ii Cells ◽  
Mrna Levels ◽  
Type Ii ◽  
Mrna Content ◽  
Type Ii Cell ◽  
Surfactant Phospholipids ◽  
Two Populations

Silica is known to cause an increase in lung surfactant and to promote type II cell hypertrophy and hyperplasia. Two populations of type II cells can be isolated from silica-treated rats: type IIA cells that are similar to normal type II cells and type IIB cells that are larger, contain more surfactant phospholipids, and have increased rates of phospholipid biosynthesis. As much less is known about the influence of silica on the amounts of surfactant proteins (SPs) in type II cells, we examined expression of the genes for all four SPs in types IIA and IIB cells isolated from rats 1, 3, and 7 days after a single intratracheal injection of silica. There was a rapid increase in expression of the SP-A gene in type II cells from the silica-treated animals. SP-A mRNA content was 8- to 10-fold greater in types IIA and IIB cells isolated 1 day after silica injection than in type II cells from saline-injected animals. SP-A mRNA levels were also elevated in the cells isolated on days 3 and 7 after silica injection, but the extent of the increase was less than in the cells isolated on day 1 and declined with time after injection. SP-B, SP-C, and SP-D mRNA levels were 2.5- to 4-fold greater in type IIA cells on day 3 after silica injection than in control type II cells. However, those mRNA levels were not significantly increased in the type IIA cells isolated on days 1 and 7 or in type IIB cells at any time point. These data show that silica causes a rapid and substantial increase in expression of the SP-A gene in type II cells.

Analysis of genomic regions involved in regulation of the rabbit surfactant protein A gene in transgenic mice

1999 ◽  
Vol 277 (2) ◽  
pp. L349-L361 ◽  
Author(s):  
Joseph L. Alcorn ◽  
Robert E. Hammer ◽  
Katherine R. Graves ◽  
Margaret E. Smith ◽  
Shanna D. Maika ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transgenic Mice ◽  
Transgene Expression ◽  
Fusion Gene ◽  
Surfactant Protein ◽  
Type Ii Cells ◽  
Type Ii ◽  
Regulation Of Expression ◽  
Camp Induction ◽  
Genomic Regions

The gene encoding surfactant protein (SP) A, a developmentally regulated pulmonary surfactant-associated protein, is expressed in a lung-specific manner, primarily in pulmonary type II cells. SP-A gene transcription in the rabbit fetal lung is increased by cAMP. To delineate the genomic regions involved in regulation of SP-A gene expression, lines of transgenic mice carrying fusion genes composed of various amounts of 5′-flanking DNA from the rabbit SP-A gene linked to the human growth hormone structural gene as a reporter were established. We found that as little as 378 bp of 5′-flanking DNA was sufficient to direct appropriate lung cell-selective and developmental regulation of transgene expression. The same region was also sufficient to mediate cAMP induction of transgene expression. Mutagenesis or deletion of either of two DNA elements, proximal binding element and a cAMP response element-like sequence, previously found to be crucial for cAMP induction of SP-A promoter activity in transfected type II cells, did not affect lung-selective or temporal regulation of expression of the transgene; however, overall levels of fusion gene expression were reduced compared with those of wild-type transgenes.

Binding and uptake of surfactant protein D by freshly isolated rat alveolar type II cells

2000 ◽  
Vol 278 (4) ◽  
pp. L830-L839 ◽  
Author(s):  
Joel F. Herbein ◽  
Jordan Savov ◽  
Jo Rae Wright
Keyword(s):  
Surfactant Protein ◽  
Surfactant Protein D ◽  
Alveolar Type ◽  
Type Ii Cells ◽  
Dependent Manner ◽  
Type Ii ◽  
Lipid Uptake ◽  
Lamellar Bodies ◽  
Alveolar Type Ii Cells ◽  
Type Ii Cell

Alveolar type II cells secrete, internalize, and recycle pulmonary surfactant, a lipid and protein complex that increases alveolar compliance and participates in pulmonary host defense. Surfactant protein (SP) D, a collagenous C-type lectin, has recently been described as a modulator of surfactant homeostasis. Mice lacking SP-D accumulate surfactant in their alveoli and type II cell lamellar bodies, organelles adapted for recycling and secretion of surfactant. The goal of current study was to characterize the interaction of SP-D with rat type II cells. Type II cells bound SP-D in a concentration-, time-, temperature-, and calcium-dependent manner. However, SP-D binding did not alter type II cell surfactant lipid uptake. Type II cells internalized SP-D into lamellar bodies and degraded a fraction of the SP-D pool. Our results also indicated that SP-D binding sites on type II cells may differ from those on alveolar macrophages. We conclude that, in vitro, type II cells bind and recycle SP-D to lamellar bodies, but SP-D may not directly modulate surfactant uptake by type II cells.

Changes in surfactant protein gene expression in a neonatal rabbit model of hyperoxia-induced fibrosis

1997 ◽  
Vol 272 (4) ◽  
pp. L720-L730 ◽  
Author(s):  
C. T. D'Angio ◽  
J. N. Finkelstein ◽  
M. B. Lomonaco ◽  
A. Paxhia ◽  
S. A. Wright ◽  
...  
Keyword(s):  
Gene Expression ◽  
In Situ Hybridization ◽  
Pulmonary Inflammation ◽  
Rabbit Model ◽  
Surfactant Protein ◽  
Type Ii Cells ◽  
Type Ii ◽  
Surfactant System ◽  
Lung Injuries

Lung injuries, including bronchopulmonary dysplasia, alter the surfactant system. We developed a newborn rabbit model of acute, followed by chronic, hyperoxic injury to study surfactant protein (SP) gene expression. Initial litters were exposed to >95% O2 until 50% died (LD50; 7-11 days old). Subsequent litters were exposed to >95% O2 for 8 days, followed by 60% O2 until 22-36 days. Controls were exposed to room air. LD50 animals displayed acute pulmonary inflammation, edema, protein leak, and surfactant dysfunction. These changes resolved, and fibrosis developed by 22 days. Whole lung SP-A mRNA expression (measured by membrane hybridization) was twice control levels at 4 days of >95% O2, with specific elevations in terminal bronchioles and type II cells at 4 days and the LD50 by in situ hybridization. Whole lung SP-B and SP-C mRNA were unchanged from control throughout exposure. However, in situ hybridization showed elevations in SP-B and SP-C mRNA in type II cells in inflamed areas at the LD50. SP mRNA alterations resolved by 22-36 days. The surfactant system recovers from acute hyperoxic injury, despite continued 60% O2 exposure.

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