title: Probing the mechanical properties of TNF-α stimulated endothelial cell with atomic force microscopy.
abstract: TNF-α (tumor necrosis factor-α) is a potent pro-inflammatory cytokine that regulates the permeability of blood and lymphatic vessels. The plasma concentration of TNF-α is elevated (> 1 pg/mL) in several pathologies, including rheumatoid arthritis, atherosclerosis, cancer, pre-eclampsia; in obese individuals; and in trauma patients. To test whether circulating TNF-α could induce similar alterations in different districts along the vascular system, three endothelial cell lines, namely HUVEC, HPMEC, and HCAEC, were characterized in terms of 1) mechanical properties, employing atomic force microscopy; 2) cytoskeletal organization, through fluorescence microscopy; and 3) membrane overexpression of adhesion molecules, employing ELISA and immunostaining. Upon stimulation with TNF-α (10 ng/mL for 20 h), for all three endothelial cells, the mechanical stiffness increased by about 50% with a mean apparent elastic modulus of E ~5 ± 0.5 kPa (~3.3 ± 0.35 kPa for the control cells); the density of F-actin filaments increased in the apical and median planes; and the ICAM-1 receptors were overexpressed compared with controls. Collectively, these results demonstrate that sufficiently high levels of circulating TNF-α have similar effects on different endothelial districts, and provide additional information for unraveling the possible correlations between circulating pro-inflammatory cytokines and systemic vascular dysfunction.
authors.affiliation: Department of Nanomedicine and Biomedical Engineering, The University of Texas Medical School at Houston, Houston, TX, USA.
authors.forename: Sei-Young
authors.initials: SY
authors.lastname: Lee
authors.forename: Ana-Maria
authors.initials: AM
authors.lastname: Zaske
authors.forename: Tommaso
authors.initials: T
authors.lastname: Novellino
authors.forename: Delia
authors.initials: D
authors.lastname: Danila
authors.forename: Mauro
authors.initials: M
authors.lastname: Ferrari
authors.forename: Jodie
authors.initials: J
authors.lastname: Conyers
authors.forename: Paolo
authors.initials: P
authors.lastname: Decuzzi
mesh_terms: D000199:Actins / Q000378:metabolism; D001696:Biomechanical Phenomena; D002448:Cell Adhesion / Q000187:drug effects; D002460:Cell Line; D016207:Cytokines / Q000502:physiology; D003599:Cytoskeleton / Q000648:ultrastructure; D055119:Elastic Modulus / Q000187:drug effects; D042783:Endothelial Cells / Q000187:drug effects* / Q000502:physiology* / Q000648:ultrastructure; D006801:Humans; D018836:Inflammation Mediators / Q000502:physiology; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D018625:Microscopy, Atomic Force; D008856:Microscopy, Fluorescence; D050997:Nanomedicine; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology* / Q000502:physiology; D014783:Viscosity / Q000187:drug effects
chemical_list: D000199:Actins; D016207:Cytokines; D018836:Inflammation Mediators; D014409:Tumor Necrosis Factor-alpha; D018799:Intercellular Adhesion Molecule-1