Pulmonary surfactant-associated protein A enhances the surface activity of lipid extract surfactant and reverses inhibition by blood proteins in vitro

Biochemistry ◽  
1990 ◽  
Vol 29 (36) ◽  
pp. 8424-8429 ◽  
Author(s):  
Amanda M. Cockshutt ◽  
Jeffrey Weitz ◽  
Fred Possmayer
Keyword(s):  
Surface Activity ◽  
Pulmonary Surfactant ◽  
Protein A ◽  
Lipid Extract ◽  
Blood Proteins

Alterations in the surface properties of lung surfactant in the torpid marsupial Sminthopsis crassicaudata

1998 ◽  
Vol 84 (1) ◽  
pp. 146-156 ◽  
Author(s):  
Olga V. Lopatko ◽  
Sandra Orgeig ◽  
Christopher B. Daniels ◽  
David Palmer
Keyword(s):  
Surface Tension ◽  
Surface Properties ◽  
Surface Activity ◽  
Pulmonary Surfactant ◽  
Lung Surfactant ◽  
Lung Compliance ◽  
Equilibrium Surface Tension ◽  
Sminthopsis Crassicaudata

Lopatko, Olga V., Sandra Orgeig, Christopher B. Daniels, and David Palmer. Alterations in the surface properties of lung surfactant in the torpid marsupial Sminthopsis crassicaudata. J. Appl. Physiol. 84(1): 146–156, 1998.—Torpor changes the composition of pulmonary surfactant (PS) in the dunnart Sminthopsis crassicaudata [C. Langman, S. Orgeig, and C. B. Daniels. Am. J. Physiol. 271 ( Regulatory Integrative Comp. Physiol. 40): R437–R445, 1996]. Here we investigated the surface activity of PS in vitro. Five micrograms of phospholipid per centimeter squared surface area of whole lavage (from mice or from warm-active, 4-, or 8-h torpid dunnarts) were applied dropwise onto the subphase of a Wilhelmy-Langmuir balance at 20°C and stabilized for 20 min. After 4 h of torpor, the adsorption rate increased, and equilibrium surface tension (STeq), minimal surface tension (STmin), and the %area compression required to achieve STmin decreased, compared with the warm-active group. After 8 h of torpor, STmin decreased [from 5.2 ± 0.3 to 4.1 ± 0.3 (SE) mN/m]; %area compression required to achieve STmindecreased (from 43.4 ± 1.0 to 27.4 ± 0.8); the rate of adsorption decreased; and STeqincreased (from 26.3 ± 0.5 to 38.6 ± 1.3 mN/m). ST-area isotherms of warm-active dunnarts and mice at 20°C had a shoulder on compression and a plateau on expansion. These disappeared on the isotherms of torpid dunnarts. Samples of whole lavage (from warm-active and 8-h torpor groups) containing 100 μg phospholipid/ml were studied by using a captive-bubble surfactometer at 37°C. After 8 h of torpor, STmin increased (from 6.4 ± 0.3 to 9.1 ± 0.3 mN/m) and %area compression decreased in the 2nd (from 88.6 ± 1.7 to 82.1 ± 2.0) and 3rd (from 89.1 ± 0.8 to 84.9 ± 1.8) compression-expansion cycles, compared with warm-active dunnarts. ST-area isotherms of warm-active dunnarts at 37°C did not have a shoulder on compression. This shoulder appeared on the isotherms of torpid dunnarts. In conclusion, there is a strong correlation between in vitro changes in surface activity and in vivo changes in lipid composition of PS during torpor, although static lung compliance remained unchanged (see Langman et al. cited above). Surfactant from torpid animals is more active at 20°C and less active at 37°C than that of warm-active animals, which may represent a respiratory adaptation to low body temperatures of torpid dunnarts.

Interaction of transferrin saturated with iron with lung surfactant in respiratory failure

1994 ◽  
Vol 77 (2) ◽  
pp. 757-766 ◽  
Author(s):  
M. Hallman ◽  
A. Sarnesto ◽  
K. Bry
Keyword(s):  
Respiratory Failure ◽  
Surface Activity ◽  
Lung Surfactant ◽  
Protein A ◽  
Surfactant Protein ◽  
Lung Damage ◽  
Epithelial Lining ◽  
Surface Absorption ◽  
Epithelial Lining Fluid

Proteins that decrease the surface activity of surfactant accumulate in epithelial lining fluid in respiratory failure. The aim of this study was to isolate a surfactant inhibitor from the airways of rabbits in acute respiratory failure induced by bronchoalveolar lavage (BAL). This inhibitor was identified as being transferrin (TF). Unlike serum TF, TF recovered in respiratory failure was saturated with iron (Fe(3+)-TF). Fe(3+)-TF decreased the surface activity of normal surfactant in vitro, whereas iron-free TF had no effect. In the presence of H2O2 and a reducing agent, Fe(+3)-TF inactivated the surfactant complex: the surface absorption rate was decreased, immunoreactive surfactant protein A was decreased, and malondialdehyde was formed. The acute effects of Fe(3+)-TF and iron-free TF applied to the airways were studied in animal models. In respiratory failure induced by BAL, Fe(3+)-TF deteriorated respiratory failure, whereas iron-free TF had no effect. In respiratory failure induced by hyperoxia for 48 h, administration of iron-free TF ameliorated the respiratory failure and improved the surface activity in BAL. We propose that Fe(3+)-TF accumulating in epithelial lining fluid during lung damage contributes to surfactant inhibition and promotes the formation of free radicals that inactivate the surfactant system.

scholarly journals Surfactant protein A inhibits T cell proliferation via its collagen-like tail and a 210-kDa receptor

1998 ◽  
Vol 275 (4) ◽  
pp. L679-L686 ◽  
Author(s):  
Paul Borron ◽  
Francis X. McCormack ◽  
Baher M. Elhalwagi ◽  
Zissis C. Chroneos ◽  
James F. Lewis ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
T Cell ◽  
T Lymphocyte ◽  
Lymphocyte Proliferation ◽  
Pulmonary Surfactant ◽  
Protein A ◽  
T Cell Proliferation ◽  
T Lymphocyte Proliferation ◽  
Human T Lymphocyte

Investigation of possible mechanisms to describe the hyporesponsiveness of pulmonary leukocytes has led to the study of pulmonary surfactant and its constituents as immune suppressive agents. Pulmonary surfactant is a phospholipid-protein mixture that reduces surface tension in the lung and prevents collapse of the alveoli. The most abundant protein in this mixture is a hydrophilic molecule termed surfactant-associated protein A (SP-A). Previously, we showed that bovine (b) SP-A can inhibit human T lymphocyte proliferation and interleukin-2 production in vitro. Results presented in this investigation showed that different sources of human SP-A and bSP-A as well as recombinant rat SP-A inhibited human T lymphocyte proliferation in a dose-dependent manner. A structurally similar collagenous protein, C1q, did not block the in vitro inhibitory action of SP-A. The addition of large concentrations of mannan to SP-A-treated cultures also did not disrupt inhibition, suggesting that the effect is not mediated by the carbohydrate recognition domain of SP-A. Use of recombinant mutant SP-As revealed that a 36-amino acid Arg-Gly-Asp (RGD) motif-containing span of the collagen-like domain was responsible for the inhibition of T cell proliferation. A polyclonal antiserum directed against an SP-A receptor (SP-R210) completely blocked the inhibition of T cell proliferation by SP-A. These results emphasize a potential role for SP-A in dampening lymphocyte responses to exogenous stimuli. The data also provide further support for the concept that SP-A maintains a balance between the clearance of inhaled pathogens and protection against collateral immune-mediated damage.

A Synthetic Segment of Surfactant Protein A: Structure, in Vitro Surface Activity, and in Vivo Efficacy

1996 ◽  
Vol 39 (6) ◽  
pp. 938-946 ◽  
Author(s):  
Frans J Walther ◽  
Remedios David-Cu ◽  
Carol Leung ◽  
Roberta Bruni ◽  
José Hernández-Juviel ◽  
...  
Keyword(s):  
Surface Activity ◽  
Protein A ◽  
Surfactant Protein ◽  
Surfactant Protein A ◽  
In Vivo Efficacy

Effects of atelectasis on pulmonary surfactant and quasi-static lung mechanics

1965 ◽  
Vol 20 (5) ◽  
pp. 859-864 ◽  
Author(s):  
Bernard E. Levine ◽  
Rudolph P. Johnson
Keyword(s):  
Surface Activity ◽  
Pulmonary Surfactant ◽  
Active Material ◽  
Extraction Procedure ◽  
Left Lung ◽  
Lung Mechanics ◽  
Normal Lung ◽  
Rabbit Lung ◽  
Surfactant Activity

The effects of unilateral atelectasis on pulmonary surfactant activity and lung mechanics have been studied in rabbits. Total left lung collapse was produced by pneumothorax and maintained from 90 min to 8 days. Quasi-static pressure-volume relationships were determined with air and saline after varying intervals. Surface activity of minced lung extracts and of dried foam obtained by tracheal washings was measured on a surface balance. A marked decrease in lung inflatability progressing with duration of collapse was noted during air and saline pressure-volume studies. However, deflation characteristics of all atelectatic lungs were normal. Extracts from minced, in vitro reinflated atelectatic lung showed a variable but significant loss of surface activity compared to the right (normal) lung of the same animal. However, highly surface-active material could be demonstrated in the collapsed lungs by the more efficient extraction procedure of tracheal foaming. Correlation exists therefore between normal volume stability of alveoli after initial inflation and presence of surfactant activity in atelectatic lungs. pressure-volume relationships; rabbit lung surface activity Submitted on July 27, 1964

scholarly journals Surface properties, morphology and protein composition of pulmonary surfactant subtypes

1996 ◽  
Vol 320 (2) ◽  
pp. 599-605 ◽  
Author(s):  
Esther PUTMAN ◽  
Lambert A. J. M. CREUWELS ◽  
Lambert M. G. van GOLDE ◽  
Henk P. HAAGSMAN
Keyword(s):  
Pulmonary Surfactant ◽  
Structural Organization ◽  
Adsorption Process ◽  
Protein A ◽  
Protein Composition ◽  
High Adsorption ◽  
Adsorption Studies ◽  
Natural Surfactants ◽  
Surfactant Metabolism

Separation of surfactant subtypes is now commonly used as a parameter in assessing the amount of active compared with inactive material in various models of lung injury. The protein content, morphology and surface activity were determined of the heavy and light subtype isolated by differential centrifugation. Here we report the presence of surfactant proteins B and C in the heavy subtype but not in the light subtype. Adsorption studies revealed that separation of fast adsorbing bronchoalveolar lavage resulted in slowly adsorbing heavy and light subtypes. Surfactant, reconstituted from heavy and light fractions, did not show a high adsorption rate. It is concluded that the isolation procedures might result in a loss of fast adsorbing surfactant structures. Surface area cycling was used as a model in vitro for the extracellular surfactant metabolism. The heavy subtype is converted into the light subtype during conversion. Conversion performed with resuspended heavy subtype revealed the generation of a disparate subtype. Furthermore it was found that the conversion was dependent on preparation and handling of the samples before cycling. Finally, adsorption studies at low surfactant concentrations revealed a delayed adsorption of lipid-extracted surfactants compared with natural surfactants. These observations emphasize the importance of the (surfactant-associated protein A-dependent) structural organization of surfactant lipids in the adsorption process.

Inhibition of surfactant activity byPneumocystis cariniiorganisms and components in vitro

2005 ◽  
Vol 288 (6) ◽  
pp. L1124-L1131 ◽  
Author(s):  
Zhengdong Wang ◽  
Adam Foye ◽  
Yusuo Chang ◽  
Patricia R. Chess ◽  
Terry W. Wright ◽  
...  
Keyword(s):  
Surface Tension ◽  
Surface Activity ◽  
Total Phospholipid ◽  
Lung Surfactant ◽  
Pneumocystis Carinii ◽  
Protein A ◽  
Dynamic Surface Tension ◽  
Chemical Components ◽  
Dynamic Surface

This study examines the direct inhibitory effects of Pneumocystis carinii ( Pc) organisms and chemical components on the surface activity and composition of whole calf lung surfactant (WLS) and calf lung surfactant extract (CLSE) in vitro. Incubation of WLS suspensions with intact Pc organisms (107per milligram of surfactant phospholipid) did not significantly alter total phospholipid levels or surfactant protein A content. Incubation with intact Pc organisms also did not impair dynamic surface tension lowering in suspensions of WLS or centrifuged large surfactant aggregates on a bubble surfactometer (37°C, 20 cycles/min, 0.5 and 2.5 mg phospholipid/ml). However, exposure of WLS or CLSE to disrupted (sonicated) Pc organisms led to severe detriments in activity, with minimum surface tensions of 17–19 mN/m vs. <1 mN/m for surfactants alone. Extracted hydrophobic chemical components from Pc (98.8% lipids, 0.1 mM) reduced the surface activity of WLS and CLSE similarly to sonicated Pc organisms, whereas extracted hydrophilic chemical components from Pc (primarily proteins) had only minor effects on surface tension lowering. These results indicate that in addition to surfactant dysfunction induced by inflammatory lung injury and edema-derived inhibitors in Pc pneumonia, disrupted Pc organisms in the alveolar lumen also have the potential to directly inhibit endogenous and exogenous lung surfactants in affected patients.

Altered function of pulmonary surfactant in fatty acid lung injury

1990 ◽  
Vol 69 (3) ◽  
pp. 1143-1149 ◽  
Author(s):  
S. B. Hall ◽  
R. H. Notter ◽  
R. J. Smith ◽  
R. W. Hyde
Keyword(s):  
Fatty Acid ◽  
Lung Injury ◽  
Surface Activity ◽  
Pulmonary Surfactant ◽  
Free Fraction ◽  
Phospholipid Content ◽  
Pulmonary Mechanics ◽  
Polymorphonuclear Cells

To determine whether acute fatty acid lung injury impairs pulmonary surfactant function, we studied anesthetized ventilated rabbits given oleic acid (55 mg/kg iv, n = 11) or an equivalent volume of saline (n = 8). Measurements of pulmonary mechanics indicated a decrease in dynamic compliance within 5 min of injury and a decrease in lung volume that was disproportionately large at low pressures, consistent with diminished surfactant activity in vivo. Bronchoalveolar lavage fluid obtained 1 h after injury had significantly increased erythrocytes and total leukocytes, largely polymorphonuclear cells. The phospholipid content and composition of the cell-free fraction had only minor changes from those of controls, but the protein content was increased 35-fold. Measurements of lavage surface activity in vitro showed an increase in average minimum surface tension from 1.3 +/- 0.4 (SE) dyn/cm in controls to 20.2 +/- 3.9 dyn/cm in injured animals. The alterations in static pressure-volume curves and decrease in lavage surface activity suggest a severe alteration of surfactant function in this form of lung injury that occurs despite the presence of normal amounts of surfactant phospholipids.

Pulmonary surfactant protein-A (SP-A) modulates human PBMC proliferation and cytokine production in vitro

Cytokine ◽  
1994 ◽  
Vol 6 (5) ◽  
pp. 539
Author(s):  
Paul Borron ◽  
L.J. Fraher ◽  
R.G. McFadden ◽  
J.F. Lewis ◽  
F. Possmayer
Keyword(s):  
Pulmonary Surfactant ◽  
Cytokine Production ◽  
Protein A ◽  
Surfactant Protein ◽  
Surfactant Protein A ◽  
Human Pbmc ◽  
Pulmonary Surfactant Protein
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