title: Cytoskeletal changes in actin and microtubules underlie the developing surface mechanical properties of sensory and supporting cells in the mouse cochlea.
abstract: Correct patterning of the inner ear sensory epithelium is essential for the conversion of sound waves into auditory stimuli. Although much is known about the impact of the developing cytoskeleton on cellular growth and cell shape, considerably less is known about the role of cytoskeletal structures on cell surface mechanical properties. In this study, atomic force microscopy (AFM) was combined with fluorescence imaging to show that developing inner ear hair cells and supporting cells have different cell surface mechanical properties with different developmental time courses. We also explored the cytoskeletal organization of developing sensory and non-sensory cells, and used pharmacological modulation of cytoskeletal elements to show that the developmental increase of hair cell stiffness is a direct result of actin filaments, whereas the development of supporting cell surface mechanical properties depends on the extent of microtubule acetylation. Finally, this study found that the fibroblast growth factor signaling pathway is necessary for the developmental time course of cell surface mechanical properties, in part owing to the effects on microtubule structure.
authors.affiliation: Section on Auditory Mechanics, Laboratory of Cellular Biology, National Institute on Deafness and other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA. szaramak@nidcd.nih.gov
authors.forename: Katherine B
authors.initials: KB
authors.lastname: Szarama
authors.forename: Núria
authors.initials: N
authors.lastname: Gavara
authors.forename: Ronald S
authors.initials: RS
authors.lastname: Petralia
authors.forename: Matthew W
authors.initials: MW
authors.lastname: Kelley
authors.forename: Richard S
authors.initials: RS
authors.lastname: Chadwick
mesh_terms: D000107:Acetylation; D008841:Actin Cytoskeleton / Q000378:metabolism* / Q000648:ultrastructure; D000199:Actins / Q000378:metabolism*; D000818:Animals; D001696:Biomechanical Phenomena / Q000502:physiology; D003051:Cochlea / Q000166:cytology* / Q000254:growth & development* / Q000502:physiology / Q000648:ultrastructure; D005346:Fibroblast Growth Factors / Q000378:metabolism; D018072:Hair Cells, Auditory, Outer / Q000166:cytology / Q000378:metabolism / Q000648:ultrastructure; D051379:Mice; D018625:Microscopy, Atomic Force; D008870:Microtubules / Q000378:metabolism*; D008954:Models, Biological; D058105:Polymerization; D015398:Signal Transduction; D013499:Surface Properties; D013997:Time Factors
chemical_list: D000199:Actins; D005346:Fibroblast Growth Factors