Influence of surfactant protein C on the interfacial behavior of phosphatidylethanolamine monolayers

Abstract

In the current work we study with monolayer tensiometry and Brewster angle microscopy (BAM) the surface properties of Dipalmitoleoylphosphatidylethanolamine (DPoPE) films at the air/water interface in presence and absence of specific surfactant protein C (SP-C). DPoPE is used, as it readily forms both lamellar (L(alpha)) and non-lamellar inverted hexagonal (H(II)) phases and appears as a suitable model phospholipid for probing the interfacial properties of distinct lipid phases. At pure air/water interface L(alpha) shows faster adsorption and better surface disintegration than H(II) phase. The interaction of DPoPE molecules with SP-C (predeposited at the interface) results in equalizing of the interfacial disintegration of the both phases (reaching approximately the same equilibrium surface tension) although the adsorption kinetics of the lamellar phase remains much faster. Monolayer compression/decompression cycling revealed that the effect of SP-C on dynamic surface tensions (gamma (max) and gamma (min)) of mixed films is remarkably different for the two phases. If gamma (max) for L(alpha) decreased from the first to the third cycle, the opposite effect is registered for H(II) where gamma (max) increases during cycling. Also the significant decrease of gamma (min) for L(alpha) in SP-C presence is not observed for H(II) phase. BAM studies reveal the formation of more uniform and homogeneously packed DPoPE monolayers in the presence of SP-C.

Phosphatidylethanolamine Induces an Antifibrotic Phenotype in Normal Human Lung Fibroblasts and Ameliorates Bleomycin-Induced Lung Fibrosis in Mice

“…In addition to the molecular mechanisms previously proposed, PE could also act in vivo by modifying the biophysical properties of surfactant. Rapid adsorption of lipids to the air-liquid interface is an essential property of lung surfactant and the hydrophobic surfactant proteins SP-B and SP-C play a crucial role in this effect but recently it has been reported that PE also induces acceleration in the adsorption rate [ 34 , 35 ]. In other experiments, aerosolized nanovesicles prepared with DPPC and dioleylphosphatidylethanolamine improved the resistance of pulmonary surfactants to inhibition in mice with acid-induced lung injury [ 36 ].…”

Influence of pH on colloidal properties and surface activity of polyglycerol fatty acid ester vesicles

“…The fast outward movement of water causes the relatively stiff membrane to partially break, so that the hydrophobic core is exposed to water. Since surfactants generally avoid the energetically unfavorable contact between hydrophobic chains and hydrophilic disper- 3 Note that the vessel of the kitchen machine contains only 3 liters and the maximum foam volume was limited by the container size. sion media, the pH-induced, morphological change of the vesicles also impacts the adsorption behavior.…”

“…7, we show the foam volume formed from 500 mL Fig. 7 clearly illustrates that the foam formation rate at low pH is much higher as almost three liters of foam are formed within only 60 s. 3 In contrast, at pH 9, the volume of foam even after 5 min of whipping was only 100 mL. Comparing these results with previous surface tension measurements, it can be found that the faster surfactant exchange rate between bulk and surface at pH 3 correlates well with the foaming power.…”

“…Besides being surface active, it is an intrinsic characteristic of surfactants to form self-assembled aggregates when present above a critical concentration in solution [2]; examples of such assemblies are micelles, vesicles and various liquid crystalline phases. In the presence of such supramolecular aggregates, the exchange rate between bulk and surface is altered and strongly depends on the nature of the self-associated structure [3,4]. Amongst the wide number of surfactants and surfactant aggregates, one particular type of structure, whose adsorption behavior to the air-water interface has been studied in great detail, are vesicles, especially vesicle dispersions of phospholipids.…”

Potential Therapeutic Applications of Pulmonary Surfactant Lipids in the Host Defence Against Respiratory Viral Infections

“…These unsaturated PCs improve the adsorption and spreading properties of surfactant at the air-liquid interface ( 8 ). Other pulmonary surfactant PLs such as PE, is important in facilitating/promoting curvature in some non-bilayer surfactant forms that are critical intermediates throughout the transitions from bilayers to interfacial films and their interconversions during surfactants metabolism ( 9 , 10 ); and PI can increase the rate of alveolar fluid clearance and stabilise the surfactant monolayer ( 7 ).…”