Differential elastic responses to barrier-altering agonists in two types of human lung endothelium

• Published in: Biochemical and biophysical research communications Vol. 478; no. 2; pp. 599 - 605
• Main Authors: Viswanathan, P., Ephstein, Y., Garcia, J.G.N., Cho, M., Dudek, S.M.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 16-09-2016
• Subjects: 60 APPLIED LIFE SCIENCES; AFM; ATOMIC FORCE MICROSCOPY; Barrier regulation; Biomechanical Phenomena; BIOMEDICAL RADIOGRAPHY; Cell Line; Cytoskeleton - metabolism; DIFFUSION BARRIERS; Elastic Modulus; ELASTICITY; Endothelial cell; Endothelium, Vascular - cytology; Endothelium, Vascular - metabolism; FTY720; GROWTH FACTORS; Hepatocyte Growth Factor - metabolism; Humans; LIVER CELLS; Lung - blood supply; LUNGS; Lysophospholipids - metabolism; Microscopy, Atomic Force; PHOSPHATES; PLANT GROWTH; Pulmonary Artery - cytology; S1P; Sphingosine - analogs & derivatives; Sphingosine - metabolism; Thrombin - metabolism; VENTILATION BARRIERS; AFM; Endothelial cell; S1P; FTY720; Barrier regulation
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2016.07.112

Vascular integrity is primarily determined by endothelial cell (EC) cytoskeletal structure that is differentially regulated by various stimuli. In this study, atomic force microscopy (AFM) was used to characterize structural and mechanical properties in the cytoskeleton of cultured human pulmonary artery EC (HPAEC) and human lung microvascular EC (HLMVEC) by determining elastic properties (Young's modulus) in response to endogenous barrier protective agents sphingosine 1-phosphate (S1P) and hepatocyte growth factor (HGF), or the barrier disruptive molecule thrombin. Initial studies in unstimulated cells indicate higher baseline peripheral elastic modulus values in HPAEC (mean 2.9 KPa) than in HLMVEC (1.8 KPa). After 30 min of stimulation, S1P induced the highest Young's modulus increase (6.1 KPa) compared to the other barrier enhancing stimuli, HGF (5.8 KPa) and the pharmaceutical agent and S1P analog FTY720 (4.1 KPa). In contrast, the barrier disruptive agent thrombin decreased values from 2.5 KPa to 0.7 KPa depending on the cell type and treatment time. AFM topographical imaging supports these quantitative biophysical data regarding differential peripheral elastic properties in EC. Overall, these AFM studies provide novel insights into the biomechanical properties of human lung EC that regulate vascular barrier function and have potential applicability to pathophysiologic vascular leak syndromes such as acute lung injury.
•AFM dynamically measures cellular biophysical properties in live endothelial cells.•Macrovascular human lung EC exhibit different biophysical responses than microvascular.•Agonists that promote EC barrier function increase peripheral elastic properties.•Provide insights into potential therapeutic modulation of human lung EC.