Mechanical properties of L929 cells measured by atomic force microscopy: effects of anticytoskeletal drugs and membrane crosslinking.
To shed light on the architecture of the cytoskeleton, we used the atomic force microscope (AFM) to measure the elasticity, viscoelasticity, and plasticity of L929 cells. The initial elastic response (Young's modulus approximately 4,000 Pa) of the cells to an applied force was followed by a slow compression of the cytoskeleton (tau 1/2 approximately equal to 10 s). When force application was terminated, the cytoskeleton underwent a sudden partial decompression and a subsequent slow, incomplete recovery. The role of the cytoskeletal elements in cell mechanics was accessed in AFM measurements carried out on cells treated with cytochalasin D, nocodazole, or colcemid. Cytochalasin D treatment reduced both elasticity (approximately 45%) and cytoplasmic viscosity (approximately 65%), whereas cells treated with nocodazole or colcemid exhibited a marked increase in elasticity (approximately 100%) and a slight increase in viscosity (approximately 15%). The AFM force measurements also provided evidence that the cell membrane and the cytoskeleton are mechanically coupled. Tightly adherent cells were stiffer than cells that were loosely attached. Moreover, cells crosslinked with either glutaraldehyde, 3, 3'-dithiobis [sulfosuccinimidylpropionate] (DTSSP), or Concanavalin A were more rigid than untreated cells. It is of interest that cells crosslinked with Concanavalin A, but not DTSSP, displayed plastic behaviors that may reflect the induction of cytoskeletal reorganization by Concanavalin A.
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Department of Physiology and Biophysics, University of Miami School of Medicine, Florida 33136, USA.
Kuhn
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Moy
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D000199:Actins / Q000187:drug effects; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D002460:Cell Line; D002462:Cell Membrane / Q000502:physiology; D003208:Concanavalin A / Q000737:chemistry; D003432:Cross-Linking Reagents / Q000737:chemistry; D015638:Cytochalasin D / Q000494:pharmacology; D003598:Cytoskeletal Proteins / Q000187:drug effects / Q000502:physiology*; D003599:Cytoskeleton / Q000187:drug effects / Q000502:physiology*; D003703:Demecolcine / Q000494:pharmacology; D004548:Elasticity / Q000187:drug effects; D005347:Fibroblasts / Q000502:physiology* / Q000648:ultrastructure; D005976:Glutaral / Q000737:chemistry; D008565:Membrane Proteins / Q000187:drug effects / Q000502:physiology*; D051379:Mice; D018625:Microscopy, Atomic Force; D008870:Microtubules / Q000187:drug effects; D015739:Nocodazole / Q000494:pharmacology; D019384:Nucleic Acid Synthesis Inhibitors / Q000494:pharmacology; D013388:Succinimides / Q000737:chemistry; D014783:Viscosity / Q000187:drug effects
D000199:Actins; D000970:Antineoplastic Agents; D003432:Cross-Linking Reagents; D003598:Cytoskeletal Proteins; D008565:Membrane Proteins; D019384:Nucleic Acid Synthesis Inhibitors; D013388:Succinimides; D003208:Concanavalin A; D015638:Cytochalasin D; C035759:3,3'-dithiobis(sulfosuccinimidyl propionate); D015739:Nocodazole; D005976:Glutaral; D003703:Demecolcine