title: Softening of the actin cytoskeleton by inhibition of myosin II.
abstract: We have investigated the mechanical properties of fibroblast cells after adding the myosin inhibitor blebbistatin and the Rho-kinase inhibitor Y-27632 by atomic force microscopy (AFM). We have observed a decrease in the elastic modulus from a value of around 20 kPa down to a value around 8 kPa on a time scale of around 30-60 min when applying the myosin inhibitor blebbistatin, whereas the Y-27632 did not show any prominent mechanical effects. From topographic images, we can conclude that, after adding blebbistatin, actin filaments are not visible any more, whereas Y-27632 did not show any prominent effects in cell morphology. This study shows that tension generated by myosin contributes to the cellular stiffness and thus can be observed by measuring the elastic modulus of cells.
authors.affiliation: Institut für Biophysik, Universität Bremen, Bremen, Germany.
authors.forename: Jan Christian
authors.initials: JC
authors.lastname: Martens
authors.forename: Manfred
authors.initials: M
authors.lastname: Radmacher
mesh_terms: D000199:Actins / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D000577:Amides / Q000494:pharmacology; D000818:Animals; D001696:Biomechanical Phenomena; D002460:Cell Line; D048430:Cell Shape / Q000187:drug effects; D003599:Cytoskeleton / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D004548:Elasticity / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000648:ultrastructure*; D006576:Heterocyclic Compounds, 4 or More Rings / Q000494:pharmacology; D018625:Microscopy, Atomic Force; D024462:Myosin Type II / Q000037:antagonists & inhibitors* / Q000187:drug effects; D011725:Pyridines / Q000494:pharmacology; D051381:Rats; D054460:rho-Associated Kinases / Q000037:antagonists & inhibitors
chemical_list: D000199:Actins; D000577:Amides; D004791:Enzyme Inhibitors; D006576:Heterocyclic Compounds, 4 or More Rings; D011725:Pyridines; C108830:Y 27632; C472645:blebbistatin; D054460:rho-Associated Kinases; D024462:Myosin Type II