Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
Nat Commun. 2020 Feb 27;11(1):1103. doi: 10.1038/s41467-020-14825-9.
Lipid-protein complexes are the basis of pulmonary surfactants covering the respiratory surface and mediating gas exchange in lungs. Cardiolipin is a mitochondrial lipid overexpressed in mammalian lungs infected by bacterial pneumonia. In addition, increased oxygen supply (hyperoxia) is a pathological factor also critical in bacterial pneumonia. In this paper we fabricate a micrometer-size graphene-based sensor to measure oxygen permeation through pulmonary membranes. Combining oxygen sensing, X-ray scattering, and Atomic Force Microscopy, we show that mammalian pulmonary membranes suffer a structural transformation induced by cardiolipin. We observe that cardiolipin promotes the formation of periodic protein-free inter-membrane contacts with rhombohedral symmetry. Membrane contacts, or stalks, promote a significant increase in oxygen gas permeation which may bear significance for alveoli gas exchange imbalance in pneumonia.
脂质-蛋白质复合物是覆盖呼吸表面并介导肺部气体交换的肺表面活性剂的基础。心磷脂是一种在线粒体中过度表达的脂质，存在于哺乳动物肺部被细菌性肺炎感染的部位。此外，增加氧气供应（高氧）也是细菌性肺炎的一个关键病理因素。在本文中，我们制造了一种基于石墨烯的微米级传感器，用于测量氧气通过肺膜的渗透。通过结合氧传感、X 射线散射和原子力显微镜，我们表明哺乳动物的肺膜会发生由心磷脂诱导的结构转变。我们观察到心磷脂促进了具有菱面体对称性的周期性、无蛋白质的膜间接触的形成。膜接触物，或“柄”，可显著增加氧气气体的渗透，这可能对肺炎中肺泡气体交换失衡具有重要意义。
