scholarly journals Localization, synthesis, and processing of surfactant protein SP-C in rat lung analyzed by epitope-specific antipeptide antibodies.

1994 ◽  
Vol 269 (32) ◽  
pp. 20318-20328 ◽  
Author(s):  
M.F. Beers ◽  
C.Y. Kim ◽  
C. Dodia ◽  
A.B. Fisher
Keyword(s):  
Surfactant Protein ◽  
Rat Lung ◽  
Antipeptide Antibodies ◽  
Synthesis And Processing

Localization of surfactant protein A (SP-A) in alveolar macrophage subpopulations of normal and fibrotic rat lung

1994 ◽  
Vol 102 (5) ◽  
pp. 345-352 ◽  
Author(s):  
M. Kasper ◽  
G. Haroske ◽  
D. Schuh ◽  
M. M�ller ◽  
R. Koslowski ◽  
...  
Keyword(s):  
Alveolar Macrophage ◽  
Protein A ◽  
Surfactant Protein ◽  
Surfactant Protein A ◽  
Rat Lung ◽  
Macrophage Subpopulations

scholarly journals Enhanced clearance of surfactant protein D during LPS-induced acute inflammation in rat lung

2001 ◽  
Vol 281 (1) ◽  
pp. L268-L277 ◽  
Author(s):  
Joel F. Herbein ◽  
Jo Rae Wright
Keyword(s):  
Host Defense ◽  
Lung Tissue ◽  
Pulmonary Surfactant ◽  
Acute Inflammation ◽  
Surfactant Protein ◽  
Enzymatic Digestion ◽  
Time Dependent ◽  
Surfactant Protein D ◽  
Rat Lung ◽  
Secretion Clearance

Pulmonary surfactant participates in the regulation of alveolar compliance and lung host defense. Surfactant homeostasis is regulated through a combination of synthesis, secretion, clearance, recycling, and degradation of surfactant components. The extracellular pool size of surfactant protein (SP) D fluctuates significantly during acute inflammation. We hypothesized that changes in SP-D levels are due, in part, to altered clearance of SP-D. Clearance pathways in rats were assessed with fluorescently labeled SP-D that was instilled into control lungs or lungs that had been treated with lipopolysaccharide (LPS) 16 h earlier. SP-D clearance from lavage into lung tissue was time dependent from 5 min to 1 h and 1.7-fold greater in LPS-treated lungs than in control lungs. Analysis of cells isolated by enzymatic digestion of lung tissue revealed differences in the SP-D-positive cell population between groups. LPS-treated lungs had 28.1-fold more SP-D-positive tissue-associated neutrophils and 193.6-fold greater SP-D association with those neutrophils compared with control lungs. These data suggest that clearance of SP-D into lung tissue is increased during inflammation and that tissue-associated neutrophils significantly contribute to this process.

Retinoic acid increases surfactant protein mRNA in fetal rat lung in culture

1996 ◽  
Vol 271 (5) ◽  
pp. L862-L868 ◽  
Author(s):  
C. W. Bogue ◽  
H. C. Jacobs ◽  
D. W. Dynia ◽  
C. M. Wilson ◽  
I. Gross
Keyword(s):  
Retinoic Acid ◽  
Dose Response ◽  
Consensus Sequence ◽  
Surfactant Protein ◽  
Rat Lung ◽  
Response Element ◽  
Response Characteristics ◽  
Receptor Complexes ◽  
Fetal Rat ◽  
Fetal Rat Lung

Retinoic acid has both early or immediate (within hours) and late (after days) effects on gene expression. We studied the early effects of retinoic acid on the surfactant protein (SP) genes. Exposure of fetal rat lung explants to all trans-retinoic acid for 4 h resulted in a significant dose-dependent increase in SP-A, -B, and -C mRNA with markedly different dose-response characteristics. The maximal (2.5x) increase in SP-A mRNA was observed with 10(-10) M retinoic acid, whereas treatment with 10(-5) M resulted in a tendency to decreased levels. In contrast, maximal stimulation of SP-C (6x) was noted at 10(-5) M retinoic acid and that of SP-B (2x) at 10(-7) to 10(-5) M retinoic acid. Similar differences in the dose-response characteristics of SP-A and SP-C were observed with 9-cis-retinoic acid. A retinoic acid response element consensus sequence was identified in the rat SP-A gene; we hypothesize that retinoic acid-receptor complexes act directly on the SP-A gene via this response element.

ATP and adenosine 3',5'-cyclic monophosphate stimulate the synthesis of surfactant protein A in rat lung

1993 ◽  
Vol 264 (5) ◽  
pp. L431-L437 ◽  
Author(s):  
A. Wali ◽  
M. F. Beers ◽  
C. Dodia ◽  
S. I. Feinstein ◽  
A. B. Fisher
Keyword(s):  
Total Protein ◽  
Protein A ◽  
Lamellar Body ◽  
Surfactant Protein ◽  
Surfactant Protein A ◽  
Enzyme Linked Immunosorbent Assay ◽  
Translational Efficiency ◽  
Rat Lung ◽  
Body Protein ◽  
Cyclic Monophosphate

Synthesis and secretion of surfactant protein A (SP-A) were studied in the isolated perfused rat lung using Trans35S-label (approximately 85% methionine, 15% cysteine) in the perfusate with or without 1 mM ATP or 0.1 mM 8-bromoadenosine 3',5',-cyclic monophosphate (8-BrcAMP) for up to 6 h of perfusion. By enzyme-linked immunosorbent assay, the SP-A content was 36 +/- 0.3% of total protein in extracellular surfactant and 10.8 +/- 1.9% of total protein in lamellar bodies of control lungs; these relativr proportions were maintained in the presence of ATP or 8-BrcAMP. Incorporation of [35S]methionine (cysteine) into the surfactant and lamellar body protein fraction could be detected at 4 h of perfusion. At 6 h, specific activity of total protein [disintegrations per minute (dpm)/micrograms)] was significantly increased in both the surfactant (54%) and lamellar body fractions (30%) under the influence of either secretagogue compared with control conditions. In the presence of ATP, there was a significant increase in the SP-A immunoprecipitable counts of 61 and 72% in extra- and intracellular compartments, respectively. However, no significant change was observed in the relative abundance of SP-A mRNA between control and secretagogue-treated lungs. This dissociation of SP-A mRNA abundance and label incorporation into protein indicates that alteration in translational efficiency or posttranslational factors may be involved in the secretagogue-induced stimulation of SP-A synthesis.

Alveolar uptake of lipid and protein components of surfactant

1991 ◽  
Vol 261 (4) ◽  
pp. L334-L340 ◽  
Author(s):  
A. B. Fisher ◽  
C. Dodia ◽  
A. Chander
Keyword(s):  
Plasma Membranes ◽  
Protein A ◽  
Surfactant Protein ◽  
Lung Lavage ◽  
Surfactant Protein A ◽  
Rat Lung ◽  
Protein Breakdown ◽  
Aqueous Fraction ◽  
Natural Surfactant ◽  
Protein Components

We investigated the clearance of radiolabeled natural surfactant from the alveolar space of the isolated perfused rat lung. 3H, 35S-natural surfactant was prepared from rat lungs that had been perfused with [methyl-3H]choline and [35S]methionine. The biosynthesized material contained greater than 95% of 3H in phosphatidylcholine (PC) and approximately 80% of 35S in surfactant protein A. Natural surfactant (1 mumol PC) was instilled into the trachea; lungs were analyzed 5 min later or after 2 h perfusion to determine surfactant uptake, defined as lung lavage-resistant 3H or 35S [% of instilled disintegrations per minute(dpm)]. Uptake at 5 min was 31.4 +/- 0.37% for 3H and 31.9 +/- 0.85% for 35S (mean +/- SE, n = 4). At 2 h, uptake was 46.6 +/- 0.96% for 3H and 45.8 +/- 1.1% for 35S (n = 7). In the presence of 0.1 mM 8-bromoadenosine 3',5'-cyclic monophosphate (8-BrcAMP), uptake at 2 h for both 3H and 35S was stimulated to approximately 57% of instilled dpm (n = 4). Microsomes and plasma membranes isolated from lung homogenates had a ratio of 3H to 35S that was similar to the original surfactant, whereas 3H/35S in isolated lamellar bodies was increased 2.1-fold. Degradation of lipid was indicated by finding 13.4 +/- 0.65% of homogenate 3H in the aqueous fraction of lung extract after 2 h perfusion; only 2.3 +/- 0.47% of 35S dpm were soluble in trichloroacetic acid, suggesting significantly less protein breakdown. Lipid degradation was increased more than twofold by 8-BrcAMP, whereas protein degradation was not changed significantly.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Surfactant protein A is localized at the corners of the pulmonary tubular myelin lattice.

1991 ◽  
Vol 39 (10) ◽  
pp. 1331-1336 ◽  
Author(s):  
W F Voorhout ◽  
T Veenendaal ◽  
H P Haagsman ◽  
A J Verkleij ◽  
L M van Golde ◽  
...  
Keyword(s):  
Protein A ◽  
Surfactant Protein ◽  
Surfactant Protein A ◽  
Alveolar Type ◽  
Type Ii ◽  
Rat Lung ◽  
Lamellar Bodies ◽  
20 Nm

Immunogold labeling on sections of a freeze-substituted tubular myelin-enriched fraction isolated from a bronchoalveolar lavage of rat lung showed that surfactant protein A (SP-A) occurs predominantly at the corners of the tubular myelin lattice. Seventy-nine percent of the gold particles were located within 20 nm from a corner. Extracellular SP-A was detected only in the tubular myelin lattice and not in vesicles or secreted lamellar bodies. Ultra-thin cryosections of rat lung fixed in vivo showed that intracellular SP-A was distributed homogeneously over the stacked membranes of lamellar bodies in alveolar Type II cells. The presence of SP-A at the corners of the tubular myelin lattice suggests an important role of this protein in the formation and/or maintenance of this highly ordered lattice.

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