title: tmie Is required for gentamicin uptake by the hair cells of mice.
abstract: The circling (cir/cir) mouse is a spontaneous model of deafness due to deletion of a 40-kb genomic region that includes the transmembrane inner ear (tmie) gene. In addition to being deaf, cir/cir mice exhibit abnormal behaviors including circling and hyperactivity. Here we investigated differences between 3-d-old (that is, before hair-cell degeneration) cir/cir and phenotypically normal (+/cir) mice and the reason underlying the degeneration of the inner ear structure of cir/cir mice. To this end, we used gentamicin, gentamicin-Texas red conjugate, and FM1-43 to investigate mechanotransducer channel activity in the hair cells of cir/cir mice; these compounds are presumed to enter hair cells through the mechanotransducer channel. Although the structure of the inner ear of +/cir mice was equivalent to that of cir/cir mice, the hair cells of cir/cir mice (unlike +/cir) did not take up gentamicin, gentamicin-Texas red conjugate, or FM1-43. These findings suggest that hair cells in cir/cir mice demonstrate abnormal maturation and mechanotransduction. In addition, our current results indicate that tmie is required for maturation and maintenance of hair cells.
authors.affiliation: School of Life Sciences and Biotechnology, Kyungpook National University, Daegu, Korea.
authors.forename: Seojin
authors.initials: S
authors.lastname: Park
authors.forename: Jeong-Han
authors.initials: JH
authors.lastname: Lee
authors.forename: Hyun-Ju
authors.initials: HJ
authors.lastname: Cho
authors.forename: Kyu-yup
authors.initials: KY
authors.lastname: Lee
authors.forename: Myoung Ok
authors.initials: MO
authors.lastname: Kim
authors.forename: Byung-Wook
authors.initials: BW
authors.lastname: Yun
authors.forename: ZaeYoung
authors.initials: Z
authors.lastname: Ryoo
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D003051:Cochlea / Q000378:metabolism / Q000473:pathology / Q000502:physiology; D005839:Gentamicins / Q000032:analysis / Q000378:metabolism; D006198:Hair Cells, Auditory / Q000378:metabolism* / Q000473:pathology / Q000502:physiology; D040542:Mechanotransduction, Cellular; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008815:Mice, Inbred Strains; D014966:Xanthenes / Q000032:analysis
chemical_list: D005839:Gentamicins; D008565:Membrane Proteins; C530887:Tmie protein, mouse; D014966:Xanthenes; C034657:Texas red