Laser nanodissection for intracellular actin stress fibers and analysis of the severed fiber retraction and regeneration behavior

The intracellular actin cytoskeleton binds to non-muscle myosin II to form stress fibers (SFs) with a diameter of several hundred nanometers, which generate intracellular tension and control cell shape and movement. SFs generate a contractile force and transmit it to focal adhesions, which is essent...

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Main Authors: Chiho KAMBE, Kazuaki NAGAYAMA
Format: Article
Language:Japanese
Published: The Japan Society of Mechanical Engineers 2025-03-01
Series:Nihon Kikai Gakkai ronbunshu
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Online Access:https://www.jstage.jst.go.jp/article/transjsme/91/944/91_24-00271/_pdf/-char/en
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author Chiho KAMBE
Kazuaki NAGAYAMA
author_facet Chiho KAMBE
Kazuaki NAGAYAMA
author_sort Chiho KAMBE
collection DOAJ
description The intracellular actin cytoskeleton binds to non-muscle myosin II to form stress fibers (SFs) with a diameter of several hundred nanometers, which generate intracellular tension and control cell shape and movement. SFs generate a contractile force and transmit it to focal adhesions, which is essential for regulation of cell adhesion to extracellular matrix and cellular sensing of extracellular mechanical environments. Although several studies have been reported on the mechanical and contractile properties of SFs, it has not been clear how completely severed SFs are repaired and regenerated. In this study, SFs located at the periphery of living myoblasts (C2C12) were severed using a pulsed laser and their contraction and repair process were analyzed by fluorescence observation. SFs immediately contracted after their severing. The contraction process of SFs was accurately fitted using the first order lag model, indicating viscoelastic behavior. We found that SFs have a potential to repair their structures: in approximately 80% of the cells, the structure of severed SFs was gradually repaired over several minutes with contraction behavior (Repaired group), but not in some cells (Unrepaired group). The contraction rate α and contraction time constant τ of the SFs in the unrepaired group tended to be larger than those of the repaired group. These results suggest that the repair process of the severed SFs is possibly affected by the intrinsic mechanical tension of the SFs and viscous resistance from the intracellular components around the SFs which is generated by the sliding motion caused by the fiber contraction.
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spelling doaj-art-cafa82176b4a4937b634c6a1df42c6472025-08-20T01:47:51ZjpnThe Japan Society of Mechanical EngineersNihon Kikai Gakkai ronbunshu2187-97612025-03-019194424-0027124-0027110.1299/transjsme.24-00271transjsmeLaser nanodissection for intracellular actin stress fibers and analysis of the severed fiber retraction and regeneration behaviorChiho KAMBE0Kazuaki NAGAYAMA1Micro-Nano Biomechanics Laboratory, Department of Mechanical Systems Engineering, Ibaraki UniversityMicro-Nano Biomechanics Laboratory, Department of Mechanical Systems Engineering, Ibaraki UniversityThe intracellular actin cytoskeleton binds to non-muscle myosin II to form stress fibers (SFs) with a diameter of several hundred nanometers, which generate intracellular tension and control cell shape and movement. SFs generate a contractile force and transmit it to focal adhesions, which is essential for regulation of cell adhesion to extracellular matrix and cellular sensing of extracellular mechanical environments. Although several studies have been reported on the mechanical and contractile properties of SFs, it has not been clear how completely severed SFs are repaired and regenerated. In this study, SFs located at the periphery of living myoblasts (C2C12) were severed using a pulsed laser and their contraction and repair process were analyzed by fluorescence observation. SFs immediately contracted after their severing. The contraction process of SFs was accurately fitted using the first order lag model, indicating viscoelastic behavior. We found that SFs have a potential to repair their structures: in approximately 80% of the cells, the structure of severed SFs was gradually repaired over several minutes with contraction behavior (Repaired group), but not in some cells (Unrepaired group). The contraction rate α and contraction time constant τ of the SFs in the unrepaired group tended to be larger than those of the repaired group. These results suggest that the repair process of the severed SFs is possibly affected by the intrinsic mechanical tension of the SFs and viscous resistance from the intracellular components around the SFs which is generated by the sliding motion caused by the fiber contraction.https://www.jstage.jst.go.jp/article/transjsme/91/944/91_24-00271/_pdf/-char/encell biomechanicsmechanobiologycytoskeletonlaser ablationviscoelastic contraction
spellingShingle Chiho KAMBE
Kazuaki NAGAYAMA
Laser nanodissection for intracellular actin stress fibers and analysis of the severed fiber retraction and regeneration behavior
Nihon Kikai Gakkai ronbunshu
cell biomechanics
mechanobiology
cytoskeleton
laser ablation
viscoelastic contraction
title Laser nanodissection for intracellular actin stress fibers and analysis of the severed fiber retraction and regeneration behavior
title_full Laser nanodissection for intracellular actin stress fibers and analysis of the severed fiber retraction and regeneration behavior
title_fullStr Laser nanodissection for intracellular actin stress fibers and analysis of the severed fiber retraction and regeneration behavior
title_full_unstemmed Laser nanodissection for intracellular actin stress fibers and analysis of the severed fiber retraction and regeneration behavior
title_short Laser nanodissection for intracellular actin stress fibers and analysis of the severed fiber retraction and regeneration behavior
title_sort laser nanodissection for intracellular actin stress fibers and analysis of the severed fiber retraction and regeneration behavior
topic cell biomechanics
mechanobiology
cytoskeleton
laser ablation
viscoelastic contraction
url https://www.jstage.jst.go.jp/article/transjsme/91/944/91_24-00271/_pdf/-char/en
work_keys_str_mv AT chihokambe lasernanodissectionforintracellularactinstressfibersandanalysisoftheseveredfiberretractionandregenerationbehavior
AT kazuakinagayama lasernanodissectionforintracellularactinstressfibersandanalysisoftheseveredfiberretractionandregenerationbehavior