title: Expression of VASP and zyxin in cochlear pillar cells: indication for actin-based dynamics?
abstract: Vasodilator-stimulated phosphoprotein (VASP) is a member of the ENA/VASP-protein family. VASP is considered to be a crucial factor in the regulation of actin dynamics, which involves processes such as motility and cell adhesion, e.g. in filopodia or growth cones. In these processes zyxin acts as an important partner of VASP and is particularly concentrated at sites where VASP-dependent actin dynamics occur. Based on indirect evidence that actin-mediated dynamics may effect the mechanical properties of the cochlea, we have investigated expression of VASP and zyxin in the postnatal and adult rat cochlea using polymerase chain reaction and Western blot approaches, as well as immunohistochemistry and confocal microscopy. Besides an expected expression in vessels and fibroblasts, VASP and zyxin expression was also observed in pillar cells. Here, the staining was restricted to the head and foot plate of the pillar cells. Onset of VASP expression in pillar cells coincided with the beginning of hearing. In pillar cells, VASP and zyxin were co-localised with pan-actin, suggesting actin-based dynamics in these cochlear cells, which until now were rather presumed to form a highly rigid bridge between the inner and outer sensory cells. Thus, pillar cells may be more dynamically involved in controlling longer-lasting mechanical properties of the cochlea as hitherto presumed.
authors.affiliation: Department of Otolaryngology, Head and Neck Surgery, University of Homburg/Saar, Kirrberger Strasse, D-66421 Homburg/Saar Germany. bernhard.schick@uniklinik-saarland.de
authors.forename: Bernhard
authors.initials: B
authors.lastname: Schick
authors.forename: Mark
authors.initials: M
authors.lastname: Praetorius
authors.forename: Martin
authors.initials: M
authors.lastname: Eigenthaler
authors.forename: Andreas
authors.initials: A
authors.lastname: Mack
authors.forename: Peter
authors.initials: P
authors.lastname: Plinkert
authors.forename: Ulrich
authors.initials: U
authors.lastname: Walter
authors.forename: Stefan
authors.initials: S
authors.lastname: Dazert
authors.forename: Marlies
authors.initials: M
authors.lastname: Knipper
mesh_terms: D000199:Actins / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D003051:Cochlea / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism*; D003599:Cytoskeleton / Q000378:metabolism; D006309:Hearing / Q000502:physiology; D007150:Immunohistochemistry; D007760:Labyrinth Supporting Cells / Q000166:cytology / Q000378:metabolism*; D040542:Mechanotransduction, Cellular / Q000502:physiology; D008667:Metalloproteins / Q000378:metabolism*; D008840:Microfilament Proteins; D010750:Phosphoproteins / Q000378:metabolism*; D011485:Protein Binding / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D000098662:Vasodilator-Stimulated Phosphoprotein
chemical_list: D000199:Actins; D015815:Cell Adhesion Molecules; D008667:Metalloproteins; D008840:Microfilament Proteins; D010750:Phosphoproteins; D000098662:Vasodilator-Stimulated Phosphoprotein