title: Cellular stiffness response to external deformation: tensional homeostasis in a single fibroblast.
abstract: Stiffness responses of fibroblasts were measured by scanning probe microscopy, following elongation or compression by deformation of an elastic substrate by 8%. The cellular stiffness, reflecting intracellular tension acting along stress fibers, decreased or increased instantly in response to the elongating or compressing stimuli, respectively. After this rapid change, the fibroblasts gradually recovered to their initial stiffness during the following 2 h, and then stabilized. The cells did not show conspicuous changes in shape after the 8% deformation during the SPM measurements. Fluorescence examination for GFP-actin demonstrated that the structure of the stress fibers was not altered noticeably by this small degree of deformation. Treatment with Y-27632, to inhibit myosin phosphorylation and abrogate cellular contractility, eliminated the change in stiffness after the mechanical elongation. These results indicate that fibroblasts possess a mechanism that regulates intracellular tension along stress fibers to maintain the cellular stiffness in a constant equilibrium state.
authors.affiliation: Division of Biological Sciences, Graduate School of Science, Hokkaido University, Sapporo, Japan. mizutani@sci.hokudai.ac.jp
authors.forename: Takeomi
authors.initials: T
authors.lastname: Mizutani
authors.forename: Hisashi
authors.initials: H
authors.lastname: Haga
authors.forename: Kazushige
authors.initials: K
authors.lastname: Kawabata
mesh_terms: D000199:Actins / Q000378:metabolism*; D000577:Amides / Q000494:pharmacology; D000818:Animals; D048430:Cell Shape / Q000502:physiology*; D003599:Cytoskeleton / Q000378:metabolism / Q000502:physiology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005347:Fibroblasts / Q000378:metabolism / Q000502:physiology*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D051379:Mice; D020527:Microscopy, Scanning Probe; D009218:Myosins / Q000378:metabolism; D041681:NIH 3T3 Cells; D010766:Phosphorylation; D011725:Pyridines / Q000494:pharmacology; D022502:Stress Fibers / Q000378:metabolism / Q000502:physiology*; D013314:Stress, Mechanical
chemical_list: D000199:Actins; D000577:Amides; D004791:Enzyme Inhibitors; D011725:Pyridines; C108830:Y 27632; D049452:Green Fluorescent Proteins; D009218:Myosins