Effects of SPA4 peptide on lipopolysaccharide-disrupted lung epithelial barrier, injury, and function in a human cell system and mouse model of lung injury.
Effects of SPA4 peptide on lipopolysaccharide-disrupted lung epithelial barrier, injury, and function in a human cell system and mouse model of lung injury.
复制标题
SPA4肽对人细胞系统和小鼠肺损伤模型中脂多糖破坏的肺上皮屏障、损伤和功能的影响
DOI：
10.14814/phy2.15353
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发表时间：
2022-07
影响因子：
2.5
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中科院分区：
文献类型：
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上皮屏障破坏、液体积聚、炎症和受损的生理机能是肺损伤的标志。在这里，我们研究了Toll样受体-4（TLR 4）相互作用SPA 4肽的结构稳定性，其对铜绿假单胞菌脂多糖（LPS）破坏的人类细胞系统上皮屏障的影响，以及LPS诱导的肺部炎症小鼠模型中的肺损伤标志物。利用圆二色谱和紫外-可见光谱研究了SPA 4肽的结构特性。在用1 μg/ml LPS攻击细胞并用10或100 μM SPA 4肽处理细胞后，测量跨上皮电阻（TEER），这是屏障功能的指标。分别用免疫印迹和免疫细胞化学方法研究紧密连接蛋白的表达和定位。用每克体重5 μg LPS对小鼠进行肝内攻击，并用50 μg SPA 4肽处理。将肺湿/干重比或水肿、血清中表面活性蛋白-D（SP-D）水平、肺功能、组织损伤、体重和体温以及存活率确定为研究参数。光谱学结果表明，在整个研究期间，不同批次的SPA 4肽之间保持了结构。用100 μM SPA 4肽处理恢复了LPS破坏的上皮屏障，这与闭锁小带（ZO）-1和occludin蛋白的定位模式相关。相应地，SPA 4肽治疗有助于抑制肺水肿和血清SP-D水平，改善一些肺功能参数，并降低LPS攻击的死亡风险。我们的研究结果表明，SPA 4肽的抗炎活性促进了肺部病理学的解决。TLR 4相互作用的SPA 4肽恢复脂多糖破坏的肺泡上皮屏障功能和紧密连接蛋白的分布。在脂多糖诱导的肺部炎症的小鼠模型中，使用SPA 4肽的治疗性处理减少肺水肿和炎症，并改善肺功能参数和存活率。
Disrupted epithelial barrier, fluid accumulation, inflammation, and compromised physiology are hallmarks of lung injury. Here we investigated the structural stability of the Toll‐like receptor‐4 (TLR4)‐interacting SPA4 peptide, its effect on Pseudomonas aeruginosa lipopolysaccharide (LPS)‐disrupted epithelial barrier in a human cell system, and lung injury markers in a mouse model of LPS‐induced lung inflammation. The structural properties of SPA4 peptide were investigated using circular dichroism and UV–VIS spectroscopy. The transepithelial electrical resistance (TEER), an indicator of barrier function, was measured after the cells were challenged with 1 μg/ml LPS and treated with 10 or 100 μM SPA4 peptide. The expression and localization of tight junction proteins were studied by immunoblotting and immunocytochemistry, respectively. Mice were intratracheally challenged with 5 μg LPS per g body weight and treated with 50 μg SPA4 peptide. The lung wet/dry weight ratios or edema, surfactant protein‐D (SP‐D) levels in serum, lung function, tissue injury, body weights, and temperature, and survival were determined as study parameters. The spectroscopy results demonstrated that the structure was maintained among different batches of SPA4 peptide throughout the study. Treatment with 100 μM SPA4 peptide restored the LPS‐disrupted epithelial barrier, which correlated with the localization pattern of Zonula Occludens (ZO)‐1 and occludin proteins. Correspondingly, SPA4 peptide treatment helped suppress the lung edema and levels of serum SP‐D, improved some of the lung function parameters, and reduced the mortality risk against LPS challenge. Our results suggest that the anti‐inflammatory activity of the SPA4 peptide facilitates the resolution of lung pathology. The TLR4‐interacting SPA4 peptide restores the lipopolysaccharide‐disrupted alveolar epithelial barrier function and distribution of tight junction proteins. Therapeutic treatment with SPA4 peptide reduces lung edema and inflammation, and improves lung function parameters and survival in a mouse model of lipopolysaccharide‐induced lung inflammation.