title: The effect of ultrasound stimulation on the cytoskeletal organization of chondrocytes seeded in three-dimensional matrices.
abstract: The impact of low-intensity diffuse ultrasound (LIDUS) stimulation on the cytoskeletal organization of chondrocytes seeded in three-dimensional (3D) scaffolds was evaluated. Chondrocytes seeded on 3D chitosan matrices were exposed to LIDUS at 5.0 MHz (approx. 15 kPa, 51 s, 4 applications/day) in order to study the organization of actin, tubulin and vimentin. The results showed that actin presented a punctate cytosolic distribution and tubulin presented a quasiparallel organization of microtubules, whereas vimentin distribution was unaffected. Chondrocytes seeded on 3D scaffolds responded to US stimulation by the disruption of actin stress fibers and were sensitive to the presence of Rho-activated kinase (ROCK) inhibitor (Y27632). The gene expression of ROCK-I, a key element in the formation of stress fibers and mDia1, was significantly upregulated under the application of US. We conclude that the results of both the cytoskeletal analyses and gene expression support the argument that the presence of punctate actin upon US stimulation was accompanied by the upregulation of the RhoA/ROCK pathway.
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Nebraska, Lincoln, NE 68516, USA.
authors.forename: Sandra
authors.initials: S
authors.lastname: Noriega
authors.forename: Gulnara
authors.initials: G
authors.lastname: Hasanova
authors.forename: Anuradha
authors.initials: A
authors.lastname: Subramanian
mesh_terms: D000199:Actins / Q000378:metabolism; D048868:Adaptor Proteins, Signal Transducing / Q000096:biosynthesis / Q000235:genetics; D000577:Amides / Q000494:pharmacology; D002470:Cell Survival / Q000502:physiology; D002478:Cells, Cultured; D019902:Chondrocytes / Q000000981:diagnostic imaging* / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D003584:Cytological Techniques / Q000379:methods; D003599:Cytoskeleton / Q000000981:diagnostic imaging* / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D000080865:Formins; D015870:Gene Expression; D006801:Humans; D008855:Microscopy, Electron, Scanning; D011725:Pyridines / Q000494:pharmacology; D015398:Signal Transduction; D022502:Stress Fibers / Q000000981:diagnostic imaging / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D054457:Tissue Scaffolds; D014404:Tubulin / Q000378:metabolism; D014463:Ultrasonography; D014746:Vimentin / Q000378:metabolism; D054460:rho-Associated Kinases / Q000096:biosynthesis / Q000235:genetics; D020742:rhoA GTP-Binding Protein / Q000096:biosynthesis / Q000235:genetics
chemical_list: D000199:Actins; D048868:Adaptor Proteins, Signal Transducing; D000577:Amides; C108962:DIAPH1 protein, human; D000080865:Formins; D011725:Pyridines; D014404:Tubulin; D014746:Vimentin; C066737:RHOA protein, human; C108830:Y 27632; C515851:ROCK1 protein, human; D054460:rho-Associated Kinases; D020742:rhoA GTP-Binding Protein