title: Induction of cell proliferation and beta-catenin expression in rat utricles in vitro.
abstract: Limited regenerative response occurs in mammalian vestibular epithelia, although vestibular hair cell regeneration in mammals has been demonstrated under a variety of experimental conditions. Beta-catenin is known to play an important role in both cell-cell adhesion and signal transduction associated with cell proliferation. This study evaluated cell proliferation activity in mammalian vestibular epithelia in organotypic culture and examined the involvement of beta-catenin in cell proliferation in vestibular epithelia. After 72 h of culture, utricles with or without induction of cell proliferation were examined. Cell proliferation was induced by brief exposure to forskolin and supplementation with fetal bovine serum. Cell proliferation activity was assessed by bromodeoxyuridine (BrdU) labeling. Immunohistochemistry was employed for analysis of cellular distribution of beta-catenin. In utricles cultured without induction of cell proliferation. BrdU labeling was not found in vestibular epithelia. Expression of beta-catenin was found in the area corresponding to the distribution of adherens junctions in vestibular epithelia. However, BrdU labeling was identified in sensory epithelia of utricles following induction of cell proliferation, although the number of BrdU-positive cells in sensory epithelia was very limited. Accumulation of beta-catenin was occasionally found in proliferating cells in sensory epithelia; however, it was not always found in BrdU-positive cells. The present findings suggest that beta-catenin may play a role in the induction of cell proliferation in mammal vestibular epithelia.
authors.affiliation: Department of Otolaryngology--Head and Neck Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Tae-Soo
authors.initials: TS
authors.lastname: Kim
authors.forename: Takayuki
authors.initials: T
authors.lastname: Nakagawa
authors.forename: Ji-Eun
authors.initials: JE
authors.lastname: Lee
authors.forename: Kiyohiro
authors.initials: K
authors.lastname: Fujino
authors.forename: Fukuichiro
authors.initials: F
authors.lastname: Iguchi
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Endo
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Naito
authors.forename: Koichi
authors.initials: K
authors.lastname: Omori
authors.forename: Phillippe P
authors.initials: PP
authors.lastname: Lefebvre
authors.forename: Juichi
authors.initials: J
authors.lastname: Ito
mesh_terms: D000818:Animals; D001973:Bromodeoxyuridine / Q000378:metabolism; D002448:Cell Adhesion / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D005576:Colforsin / Q000494:pharmacology; D003598:Cytoskeletal Proteins / Q000378:metabolism* / Q000502:physiology; D004848:Epithelium / Q000378:metabolism; D018069:Hair Cells, Vestibular / Q000502:physiology*; D007150:Immunohistochemistry; D009924:Organ Culture Techniques; D051381:Rats; D017208:Rats, Wistar; D012038:Regeneration / Q000502:physiology*; D012444:Saccule and Utricle / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology; D014018:Tissue Distribution / Q000502:physiology; D015534:Trans-Activators / Q000378:metabolism* / Q000502:physiology; D051176:beta Catenin
chemical_list: C495268:Ctnnb1 protein, rat; D003598:Cytoskeletal Proteins; D015534:Trans-Activators; D051176:beta Catenin; D005576:Colforsin; D001973:Bromodeoxyuridine