Immuno-Electron Microscopic Study of Keratin Distribution in the Cochlea Using Monoclonal Antibody

Abstract

Keratin distribution in the cochlea has been studied immuno-electron microscopically by both pre-embedding and postembedding methods. Keratin immunoreactivity in the guinea pig cochlea was clearly demonstrated in Hensen's cells, the reticular lamina surrounding both outer and inner hair cells, outer and inner pillar cells, Claudius' cells, inner and external sulcus cells, interdental cells of the spiral limbus, Reissner's membrane, border cells, inner phalangeal cells, Deiters' cells, and spiral prominence cells. Keratin expression at the ultrastructural level showed a nonfilamentous keratin system in the cytoplasm of cochlear supporting cells.

Mitochondrial A7445G mutation in two pedigrees with palmoplantar keratoderma and deafness

“…Immunohistochemical analyses have demonstrated complex patterns of cytokeratin expression in the epithelial lining of the inner ear [Kuijpers et al, 1991;Bauwens et al, 1991] including expression of Ck10, a cytokeratin typical of keratinising squamous epithelia, in the endolymphatic duct and sac of human fetuses [Anniko et al, 1989]. Moreover interactions between mitochondria and cytokeratins do occur: incubation of rat hepatocytes with glucagon yielded a phosphorylated 20kD protein associated with the inner mitochondrial membrane fraction which consisted of terminal fragments of cytokeratin C8 [Gorlach et al, 1995]; and an immuno-electron microscopic study of the cochlea found keratins were localised in a nonfilamentous system with the mitochondria being surrounded by that system [Shi et al, 1990]. The significance of these observations in relation to normal cellular function, and perhaps to the effects of the A7445G mutation, remain to be elucidated.…”

Distribution of Cytokeratins in the Vestibular Epithelium of the Guinea Pig

“…Cochleae from these animals were processed simultaneously as control tissue, since the distribution of cytokeratins in the cochlea has been previously described. [10][11][12] The crista ampullaris of each canal (lateral, superior, and posterior), utricle, and saccule was studied.…”

Keratin filament deployment and cytoskeletal networking in a sensory epithelium that vibrates during hearing

“…The presence of filament arrays that extend throughout the regions where antibody binding has been reported has not been demonstrated at the ultrastructural level. It has been suggested that there is a nonfilamentous keratin system in the cytoplasm of these cells [Shi et al, 1990]. Keratin filament contributions to maintenance of the overall mechanical strength and properties of epithelial tissues is dependent on the structural integration of the filaments across boundaries between cell neighbors, which is usually achieved by desmosomes [Garrod, 1993;Schmidt et al, 1994;Chou et al, 1997].…”