biostudies-literatureArce FTNHLBI NIH HHS886-94https://www.ebi.ac.uk/biostudies/studies/S-EPMC2440433biostudies-literatureUnknown95(2)Disruption of pulmonary endothelial cell (EC) barrier function is a critical pathophysiologic event in highly morbid inflammatory conditions such as sepsis and acute respiratory disease stress syndrome. Actin cytoskeleton, an essential regulator of endothelial permeability, is a dynamic structure whose stimuli-induced rearrangement is linked to barrier modulation. Here, we used atomic force microscopy to characterize structural and mechanical changes in the F-actin cytoskeleton of cultured human pulmonary artery EC in response to both barrier-enhancing (induced by sphingosine 1-phosphate (S1P)) and barrier-disrupting (induced by thrombin) conditions. Atomic force microscopy elasticity measurements show differential effects: for the barrier protecting molecule S1P, the elastic modulus was eBiophysical journalRegulation of the micromechanical properties of pulmonary endothelium by S1P and thrombin: role of cortactin.PMC2440433P01 HL058064R01 HL088144K08 HL070013P01 HL 58064KO8 HL70013Arce FTLal RArnsdorf MFWhitlock JLBirukov KGGarcia JGBirukova AADudek SMfalseRegulation of the micromechanical properties of pulmonary endothelium by S1P and thrombin: role of cortactin.Disruption of pulmonary endothelial cell (EC) barrier function is a critical pathophysiologic event in highly morbid inflammatory conditions such as sepsis and acute respiratory disease stress syndrome. Actin cytoskeleton, an essential regulator of endothelial permeability, is a dynamic structure whose stimuli-induced rearrangement is linked to barrier modulation. Here, we used atomic force microscopy to characterize structural and mechanical changes in the F-actin cytoskeleton of cultured human pulmonary artery EC in response to both barrier-enhancing (induced by sphingosine 1-phosphate (S1P)) and barrier-disrupting (induced by thrombin) conditions. Atomic force microscopy elasticity measurements show differential effects: for the barrier protecting molecule S1P, the elastic modulus was e2008-01-01T00:00:00Z2008 Jul2025-06-01T01:08:53.667Z2019-06-06T18:36:38ZS-EPMC24404331840803910.1529/biophysj.107.127167