Surfactant protein A regulates cytokine production in the monocytic cell line THP-1

1997 ◽  
Vol 272 (5) ◽  
pp. L996-L1004 ◽  
Author(s):  
S. G. Kremlev ◽  
T. M. Umstead ◽  
D. S. Phelps
Keyword(s):  
Cell Line ◽  
Cytokine Production ◽  
Protein A ◽  
Surfactant Protein ◽  
Surfactant Protein A ◽  
Tnf Alpha ◽  
Enzyme Linked Immunosorbent Assay ◽  
Mrna Levels ◽  
Monocytic Cell ◽  
Monocytic Cell Line

Surfactant lipids inhibit cytokine production by immune cells, and surfactant protein A (SP-A) stimulates it. By enzyme-linked immunosorbent assay and mRNA blotting, we studied proinflammatory cytokine production by the monocytic cell line THP-1. SP-A caused increases in tumor necrosis factor (TNF)-alpha within 1 h, peaking at 4 h and then declining. Interleukin (IL)-1 beta increased and stayed elevated for 24 h. SP-A stimulated IL-8 also, peaking at 4 h, rapidly declining, and peaking again at 24 h. SP-A-dependent changes were detected for IL-6, but at higher SP-A doses. mRNA levels for TNF-alpha and IL-1 beta increased in response to SP-A, peaking within 2 h. The increases in TNF-alpha mRNA and protein induced by SP-A were inhibited by surfactant lipids. For IL-1 beta and IL-8, the lipids either had no inhibitory influence or inhibited less than for TNF-alpha. This suggests that the ability of macrophages to participate in inflammatory reactions is enhanced by SP-A alone or by mixtures of lipids and SP-A containing more SP-A than in normal surfactant, as occurs in many conditions leading to inflammation.

Postnatal stimulation of rat surfactant protein A synthesis by dexamethasone

1989 ◽  
Vol 257 (2) ◽  
pp. L137-L143 ◽  
Author(s):  
J. Floros ◽  
D. S. Phelps ◽  
H. P. Harding ◽  
S. Church ◽  
J. Ware
Keyword(s):  
Protein A ◽  
Hormone Treatment ◽  
Surfactant Protein ◽  
Surfactant Protein A ◽  
Enzyme Linked Immunosorbent Assay ◽  
Mrna Levels ◽  
Dexamethasone Treatment ◽  
Maximal Stimulation ◽  
Treatment Dose

The effects of postnatal dexamethasone treatment in vivo on the synthesis of surfactant protein A (SP-A) were examined at the protein and RNA levels. Rats ranging from 1 day old to adult were injected with 200 micrograms of dexamethasone/kg body wt or with vehicle alone and were killed 24 h after injection. One portion of the lung was metabolically labeled with [35S]methionine, the proteins immunoprecipitated using an antiserum to SP-A, and analyzed electrophoretically. Both newly synthesized intracellular and secreted SP-A levels were increased by dexamethasone, reaching averages of 2.3 and 4.5 times control values, respectively. Another portion of the lung tissue was used for RNA analysis. SP-A mRNA levels were also elevated an average of 1.4 times control values by hormone treatment. Dose-response experiments using 16-day-old pups showed that both total SP-A, as measured by enzyme-linked immunosorbent assay, and total SP-A mRNA levels were elevated with dexamethasone treatment, reaching maximal stimulation at 2 mg. We conclude that postnatal dexamethasone treatment in vivo results in increased levels of both newly synthesized SP-A and SP-A mRNA, suggesting that pretranslational events may in part contribute to this process.

Surfactant protein A inhibits alveolar macrophage cytokine production by CD14-independent pathway

2004 ◽  
Vol 286 (1) ◽  
pp. L129-L136 ◽  
Author(s):  
John F. Alcorn ◽  
Jo Rae Wright
Keyword(s):  
Alveolar Macrophages ◽  
Cytokine Production ◽  
Protein A ◽  
Surfactant Protein ◽  
Surfactant Protein A ◽  
Null Mouse ◽  
Mrna Levels ◽  
Wild Type ◽  
Independent Manner ◽  
Tnf Α

The lung collectin surfactant protein A (SP-A) has both anti-inflammatory and prophagocytic activities. We and others previously showed that SP-A inhibits the macrophage production of tumor necrosis factor (TNF)-α stimulated by the gram-negative bacterial component LPS. We propose that SP-A decreases the production of proinflammatory cytokines by alveolar macrophages via a CD14-independent mechanism. SP-A inhibited LPS-simulated TNF-α production in rat and mouse macrophages in the presence and absence of serum (72% and 42% inhibition, respectively). In addition, SP-A inhibited LPS-induced mRNA levels for TNF-α, IL-1α, and IL-1β as well as NF-κB DNA binding activity. SP-A also diminished ultrapure LPS-stimulated TNF-α produced by wild-type and CD14-null mouse alveolar macrophages by 58% and 88%, respectively. Additionally, SP-A inhibited TNF-α stimulated by PMA in both wild-type and TLR4-mutant macrophages. These data suggest that SP-A inhibits inflammatory cytokine production in a CD14-independent manner and also by mechanisms independent of the LPS signaling pathway.

Surfactant protein A activates NF-kappa B in the THP-1 monocytic cell line

1997 ◽  
Vol 273 (2) ◽  
pp. L382-L388 ◽  
Author(s):  
M. Koptides ◽  
T. M. Umstead ◽  
J. Floros ◽  
D. S. Phelps
Keyword(s):  
Cell Line ◽  
Cell Function ◽  
Immune Cell ◽  
Surfactant Protein ◽  
Surface Proteins ◽  
Mrna Levels ◽  
Nf Kappa B ◽  
Simultaneous Treatment ◽  
Monocytic Cell ◽  
Monocytic Cell Line

The expression of many genes for which products are involved in inflammation is controlled by the transcriptional regulator nuclear factor (NF)-kappa B. Because surfactant protein (SP) A is involved in local host defense in the lung and alters immune cell function by modulating the expression of proinflammatory cytokines as well as surface proteins involved in inflammation, we hypothesized that SP-A exerts its action, at least in part, via activation of NF-kappa B. We used gel shift assays to determine whether SP-A activated NF-kappa B in the THP-1 cell line, a human monocytic cell line. Activation of NF-kappa B in THP-1 cells by SP-A doses as low as 1 microgram/ml occurred within 30 min of SP-A treatment, peaked at 60 min, and then declined. This activation is inhibited by known inhibitors of NF-kappa B or by simultaneous treatment of the cells with surfactant lipids. Moreover, the NF-kappa B inhibitors blocked SP-A-dependent increases in tumor necrosis factor-alpha mRNA levels. These observations suggest a mechanism by which SP-A plays a role in the pathogenesis of some lung conditions and point to potential therapeutic measures that could be used to prevent SP-A induced inflammation in the lung.

scholarly journals Surfactant protein A reduces TLR4 and inflammatory cytokine mRNA levels in neonatal mouse ileum

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lidan Liu ◽  
Chaim Z. Aron ◽  
Cullen M. Grable ◽  
Adrian Robles ◽  
Xiangli Liu ◽  
...  
Keyword(s):  
Proinflammatory Cytokine ◽  
Inflammatory Cytokine ◽  
Protein A ◽  
Surfactant Protein ◽  
Surfactant Protein A ◽  
Mrna Levels ◽  
Wild Type ◽  
Cytokine Mrna ◽  
Protein Levels ◽  
Cytokine Levels

AbstractLevels of intestinal toll-like receptor 4 (TLR4) impact inflammation in the neonatal gastrointestinal tract. While surfactant protein A (SP-A) is known to regulate TLR4 in the lung, it also reduces intestinal damage, TLR4 and inflammation in an experimental model of necrotizing enterocolitis (NEC) in neonatal rats. We hypothesized that SP-A-deficient (SP-A−/−) mice have increased ileal TLR4 and inflammatory cytokine levels compared to wild type mice, impacting intestinal physiology. We found that ileal TLR4 and proinflammatory cytokine levels were significantly higher in infant SP-A−/− mice compared to wild type mice. Gavage of neonatal SP-A−/− mice with purified SP-A reduced ileal TLR4 protein levels. SP-A reduced expression of TLR4 and proinflammatory cytokines in normal human intestinal epithelial cells (FHs74int), suggesting a direct effect. However, incubation of gastrointestinal cell lines with proteasome inhibitors did not abrogate the effect of SP-A on TLR4 protein levels, suggesting that proteasomal degradation is not involved. In a mouse model of experimental NEC, SP-A−/− mice were more susceptible to intestinal stress resembling NEC, while gavage with SP-A significantly decreased ileal damage, TLR4 and proinflammatory cytokine mRNA levels. Our data suggests that SP-A has an extrapulmonary role in the intestinal health of neonatal mice by modulating TLR4 and proinflammatory cytokines mRNA expression in intestinal epithelium.

Antisense inhibition of surfactant protein A decreases tubular myelin formation in human fetal lung in vitro

2002 ◽  
Vol 282 (3) ◽  
pp. L386-L393 ◽  
Author(s):  
Jonathan M. Klein ◽  
Troy A. McCarthy ◽  
John M. Dagle ◽  
Jeanne M. Snyder
Keyword(s):  
Gene Expression ◽  
Protein A ◽  
Fetal Lung ◽  
Surfactant Protein ◽  
Surfactant Protein A ◽  
Mrna Levels ◽  
Phosphorothioate Oligonucleotide ◽  
Myelin Formation ◽  
Surfactant Phospholipids ◽  
Human Fetal Lung

Surfactant protein A (SP-A) is the most abundant of the surfactant-associated proteins. SP-A is involved in the formation of tubular myelin, the modulation of the surface tension-reducing properties of surfactant phospholipids, the metabolism of surfactant phospholipids, and local pulmonary host defense. We hypothesized that elimination of SP-A would alter the regulation of SP-B gene expression and the formation of tubular myelin. Midtrimester human fetal lung explants were cultured for 3–5 days in the presence or absence of an antisense 18-mer phosphorothioate oligonucleotide (ON) complementary to SP-A mRNA. After 3 days in culture, SP-A mRNA was undetectable in antisense ON-treated explants. After 5 days in culture, levels of SP-A protein were also decreased by antisense treatment. SP-B mRNA levels were not affected by the antisense SP-A ON treatment. However, there was decreased tubular myelin formation in the antisense SP-A ON-treated tissue. We conclude that selective elimination of SP-A mRNA and protein results in a decrease in tubular myelin formation in human fetal lung without affecting SP-B mRNA. We speculate that SP-A is critical to the formation of tubular myelin during human lung development and that the regulation of SP-B gene expression is independent of SP-A gene expression.

Transcriptional activation and protein binding by two regions of the rat surfactant protein A promoter

1999 ◽  
Vol 277 (1) ◽  
pp. L134-L141
Author(s):  
Elizabeth Rosenberg ◽  
Feng Li ◽  
Candyce I. Smith ◽  
Samuel R. Reisher ◽  
Sheldon I. Feinstein
Keyword(s):  
Cell Line ◽  
Cell Lines ◽  
Promoter Activity ◽  
Protein A ◽  
Surfactant Protein ◽  
Clara Cell ◽  
Surfactant Protein A ◽  
Type Ii ◽  
Recognition Element ◽  
Type Ii Cell

Surfactant protein A (SP-A) is expressed in lung alveolar type II cells and bronchiolar Clara cells. We have identified two active regions in the promoter of the rat SP-A gene by deletion analysis of a plasmid containing 163 bp before the start of transcription (−163 bp), linked to a reporter gene. Constructs were transfected into lung cell lines derived from each of the cell types that produces SP-A. We found a novel region of promoter activity at ∼90 bp before the transcriptional start (SP-A−90). Mutation of four nucleotides in SP-A−90 that are highly conserved among species (−92 to −89 bp) decreased expression of the SP-A construct by ∼50% in both cell lines. Electrophoretic mobility shift analysis showed specific binding to SP-A−90 by nuclear proteins from the cell lines, as well as from rat lung and liver. The electrophoretic mobility of the bands shifted by lung nuclear proteins changed late in fetal development. Although in the Clara cell line no reduction of promoter activity was seen on deletion of the region upstream of SP-A−90, in the type II cell line, deletion of residues −163 to −133 did reduce activity by ∼50%. This region contains a recognition element for thyroid transcription factor-1 (TTF-1). Endogenous TTF-1 binding activity was substantially higher in the type II cell line than in the Clara cell line, but cotransfection of a TTF-1 expression plasmid enhanced expression of the SP-A construct better in the Clara cell line than in the type II cell line. These results suggest that the recognition element for TTF-1 has varying activity in the lung cell lines of different origin due to the availability of TTF-1.

scholarly journals Jaagsiekte Sheep Retrovirus Proviral Clone JSRVJS7, Derived from the JS7 Lung Tumor Cell Line, Induces Ovine Pulmonary Carcinoma and Is Integrated into the Surfactant Protein A Gene

2001 ◽  
Vol 75 (9) ◽  
pp. 4239-4246 ◽  
Author(s):  
James C. DeMartini ◽  
Jeanette V. Bishop ◽  
Thomas E. Allen ◽  
F. A. Jassim ◽  
J. Michael Sharp ◽  
...  
Keyword(s):  
Tumor Cell ◽  
Cell Line ◽  
Lung Tumor ◽  
Protein A ◽  
Tumor Cell Line ◽  
Surfactant Protein ◽  
Surfactant Protein A ◽  
Jaagsiekte Sheep Retrovirus ◽  
Pulmonary Carcinoma ◽  
Lung Tumor Cell

ABSTRACT Ovine pulmonary carcinoma (OPC) is a contagious neoplasm of alveolar epithelial type II (ATII) or Clara cells caused by a type D/B chimeric retrovirus, jaagsiekte sheep retrovirus (JSRV). Here we report the isolation, sequencing, pathogenicity, and integration site of a JSRV provirus isolated from a sheep lung tumor cell line (JS7). The sequence of the virus was 93 to 99% identical to other JSRV isolates and contained all of the expected open reading frames. To produce virions and test its infectivity, the JS7 provirus (JSRVJS7) was cloned into a plasmid containing a cytomegalovirus promoter and transfected into 293T cells. After intratracheal inoculation with virions from concentrated supernatant fluid, JSRV-associated OPC lesions were found in one of four lambs, confirming that JSRVJS7 is pathogenic. In JS7-cell DNA, the viral genome was inserted in the protein-coding region for the surfactant protein A (SP-A) gene, which is highly expressed in ATII cells, in an orientation opposite to the direction of transcription of the SP-A gene. No significant transcription was detected from either the viral or the SP-A gene promoter in the JS7 cell line at passage level 170. The oncogenic significance of the JSRV proviral insertion involving the SP-A locus in the JS7 tumor cell line is unknown.

R460 – Relation Between SPA and Symptoms of Patients With AR and NP

2008 ◽  
Vol 139 (2_suppl) ◽  
pp. P199-P199
Author(s):  
Deng Yuqin ◽  
Zezhang Tao ◽  
Yonggang Kong
Keyword(s):  
Allergic Rhinitis ◽  
Indirect Immunofluorescence ◽  
Nasal Polyposis ◽  
Protein A ◽  
Upper Airway ◽  
Surfactant Protein ◽  
Surfactant Protein A ◽  
Enzyme Linked Immunosorbent Assay ◽  
Immunofluorescence Method ◽  
Defensive Role

Problem The aim of this study was to examine if allergic rhinitis and nasal polyposis are associated with the level of surfactant protein-A. Methods Sinus mucosal biopsies were performed in patients with allergic rhinitis (n= 15), nasal polyposis (n=21) and controls (n= 10). Immunolocalization of surfactant protein was performed with antibodies to SP-A using Streptavidin Peroxidase Conjugated Method and indirect immunofluorescence method. Blood serums were obtained from three subjects in each group for enzyme-linked immunosorbent assay (ELISA) analysis of surfactant protein-A. Results By ELISA, AR (n =15) and NP (n = 21) showed significantly decreased levels of SP-A when compared with controls (n= 10), although these two groups were not statistically significant. Immunohistochemical investigation showed intense SP-A staining in the nasal epithelium of each groups, but weak staining in patients with AR and NP. Conclusion We report for the first time the expression of SP-A in both diseased and normal nasal mucosa using the indirect immunofluorescence method. There was an inverse relation between surfactant protein-A levels and symptoms and signs of rhinitis in patients with AR and NP. Significance SP-A may play a defensive role in the chronic inflammatory diseases of upper airway. Understanding the exact role of SP-A in the upper airway diseases will help develop novel treatment approaches for sinonasal pathoses.

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