Mechanical properties of alveolar epithelial cells in culture.
With the use of magnetic twisting cytometry, we characterized the mechanical properties of rat type II alveolar epithelial (ATII) cells in primary culture and examined whether the cells' state of differentiation and the application of deforming stresses influence their resistance to shape change. Cells were harvested from rat lungs as previously described (Dobbs LG. Am J Physiol Lung Cell Mol Physiol 258: L134-L147, 1990) and plated at a density of 1 x 10(6) cells/cm(2) in fibronectin-coated 96 Remova wells, and their mechanical properties were measured 2-9 days later. We show 1) that ATII cells form much stronger bonds with RGD-coated beads than they do with albumin- or acetylated low-density lipoprotein-coated beads, 2) that RGD-mediated bonds seemingly "mature" during the first 60 min of bead contact, 3) that the apparent stiffness of ATII cells increases with days in culture, 4) that stiffness falls when the RGD-coated beads are intermittently oscillated at 0.3 Hz, and 5) that this fall cannot be attributed to exocytosis-related remodeling of the subcortical cytoskeleton. Although the mechanisms of force transfer between basement membrane, cytoskeleton, and plasma membrane of ATII cells remain to be resolved, such analyses undoubtedly require definition of the cell's mechanical properties. To our knowledge, the results presented here provide the first data on this topic.
Berrios
J C
JC
Thoracic Diseases Research Unit, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Mayo Clinic and Foundation, Rochester, Minnesota 55905, USA.
Schroeder
M A
MA
Hubmayr
R D
RD
D000818:Animals; D002478:Cells, Cultured; D016922:Cellular Senescence / Q000502:physiology; D003599:Cytoskeleton / Q000502:physiology; D004548:Elasticity; D004847:Epithelial Cells / Q000502:physiology; D016023:Integrins / Q000378:metabolism; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D008077:Lipoproteins, LDL; D008863:Microspheres; D009842:Oligopeptides / Q000378:metabolism; D011650:Pulmonary Alveoli / Q000166:cytology / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012709:Serum Albumin; D013314:Stress, Mechanical; D013997:Time Factors
D016023:Integrins; D008077:Lipoproteins, LDL; D009842:Oligopeptides; D012709:Serum Albumin; C032629:acetyl-LDL; D018799:Intercellular Adhesion Molecule-1; C047981:arginyl-glycyl-aspartic acid