Bacterial Lipopolysaccharide Promotes Destabilization of Lung Surfactant-Like Films
Bacterial Lipopolysaccharide Promotes Destabilization of Lung Surfactant-Like Films
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DOI：
10.1016/j.bpj.2010.11.028
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发表时间：
2011-01-05
影响因子：
3.4
通讯作者：
Casals, Cristina
中科院分区：
文献类型：
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作者：
Canadas, Olga;Keough, Kevin M. W.;Casals, Cristina
气腔内衬有富含二棕榈酰磷脂酰胆碱 (DPPC) 的薄膜，称为肺表面活性剂，因其能够通过降低气液界面的表面张力来维持正常的呼吸力学而得名。含有细菌脂多糖 (LPS) 的吸入空气颗粒可能会融入表面活性剂单层中。在本研究中，我们评估了包含整个核心寡糖区域和 O 抗原的平滑脂多糖 (S-LPS) 对由 DPPC 或 DPPC/棕榈酰油酰磷脂酰甘油 (POPG)/棕榈酸 (PA)（28:9:5.6，w/w/w）组成的肺表面活性剂样膜的生物物理特性的影响。我们的结果表明，S-LPS 流态化 DPPC 单层的含量较低，如荧光显微镜和压缩模量的变化所证明的那样。这促进了早期塌陷并阻止了高表面压力的达到。这些不稳定效应无法通过重复的压缩-膨胀循环来缓解。由 DPPC/POPG/PA 组成的类表面活性剂薄膜也观察到了类似的效果。另一方面，SP-A（一种也与 LPS 结合的表面活性剂膜相关肺泡蛋白）与含有 S-LPS 的类表面活性剂膜的相互作用，由于从单层中提取脂质分子而增加了单层不稳定，导致单层材料溶解在水相下相中。这表明 SP-A 可能充当 LPS 清除剂。
The airspaces are lined with a dipalmitoylphosphatidylcholine (DPPC)-rich film called pulmonary surfactant, which is named for its ability to maintain normal respiratory mechanics by reducing surface tension at the air-liquid interface. Inhaled airborne particles containing bacterial lipopolysaccharide (LPS) may incorporate into the surfactant monolayer. In this study, we evaluated the effect of smooth LPS (S-LPS), containing the entire core oligosaccharide region and the O-antigen, on the biophysical properties of lung surfactant-like films composed of either DPPC or DPPC/palmitoyloleoylphosphatidylglycerol (POPG)/palmitic acid (PA) (28:9:5.6, w/w/w). Our results show that low amounts of S-LPS fluidized DPPC monolayers, as demonstrated by fluorescence microscopy and changes in the compressibility modulus. This promoted early collapse and prevented the attainment of high surface pressures. These destabilizing effects could not be relieved by repeated compression-expansion cycles. Similar effects were observed with surfactant-like films composed of DPPC/POPG/PA. On the other hand, the interaction of SP-A, a surfactant membrane-associated alveolar protein that also binds to LPS, with surfactant-like films containing S-LPS increased monolayer destabilization due to the extraction of lipid molecules from the monolayer, leading to the dissolution of monolayer material in the aqueous subphase. This suggests that SP-A may act as an LPS scavenger.