Kim Tae-Soo, Nakagawa Takayuki, Lee Ji-Eun, Fujino Kiyohiro, Iguchi Fukuichiro, Endo Tsuyoshi, Naito Yasushi, Omori Koichi, Lefebvre Phillippe P, Ito Juichi
Department of Otolaryngology--Head and Neck Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Acta Otolaryngol Suppl. 2004 Mar(551):22-5. doi: 10.1080/03655230310016672.
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.
尽管在多种实验条件下已证实哺乳动物的前庭毛细胞可再生，但哺乳动物前庭上皮的再生反应有限。已知β-连环蛋白在细胞间黏附以及与细胞增殖相关的信号转导中均发挥重要作用。本研究评估了器官型培养中哺乳动物前庭上皮的细胞增殖活性，并检测了β-连环蛋白在前庭上皮细胞增殖中的作用。培养72小时后，对诱导或未诱导细胞增殖的椭圆囊进行检查。通过短暂暴露于福斯高林并补充胎牛血清来诱导细胞增殖。通过溴脱氧尿苷（BrdU）标记评估细胞增殖活性。采用免疫组织化学分析β-连环蛋白的细胞分布。在未诱导细胞增殖的培养椭圆囊中，前庭上皮未发现BrdU标记。在与前庭上皮黏着连接分布相对应的区域发现了β-连环蛋白的表达。然而，在诱导细胞增殖后，椭圆囊的感觉上皮中可检测到BrdU标记，尽管感觉上皮中BrdU阳性细胞数量非常有限。偶尔在感觉上皮的增殖细胞中发现β-连环蛋白的积累；然而，并非总是在BrdU阳性细胞中发现。目前的研究结果表明，β-连环蛋白可能在哺乳动物前庭上皮细胞增殖的诱导中发挥作用。
