Journal of the Korean Balance Society  2005;4(2):243-249

Expression of Caveolin-1 in the Differentiated Vestibular Cell Line (UB/UE-1) after Gentamicin Toxicity.

Byung Han CHO 1 ; Kyu Sung KIM ; Min Wook KIM ; Min Sun KIM ; Byung Rim PARK

Affiliations

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Keywords

Caveolin; Gentamicin; Ototoxicity

Country

Republic of Korea

Language

Korean

Abstract

BACKGROUND AND OBJECTIVES: The caveolin is known as a mediator of cell death or survival of injured cell and inhibitor of various signaling pathways. We examined expression of caveolin-1 involved by protein kinase A(PKA) signaling pathway in the differentiated mouse vestibular cell line(UB/UE-1) after gentamicin toxicity. MATERIALS AND METHOD: We observed caveolae in the vestibular hair cell of healthy guinea pig through electron microscope. UB/UE-1 cells were cultured at 95% CO2, 5% O2, 33DegreeC for 2days and at 95% CO2, 5% O2, 39DegreeC for 24 hours for differentiation. Cells were treated with 1 mM of gentamicin, 0.02 mM H89 (PKA inhibitor), and then incubated for 24 hours. Caveolin-1 expression was examined by western blot and PKA activity by PepTag? assay. RESULTS: Caveolae were observed in the vestibular hair cell of healthy guinea pig by electron microscope. Caveolin-1 was expressed spontaneously in differentiated UB/UE-1 cells and increased after gentamicin treatment. PKA is overactivated by gentamicin treatment. The gentamicin induced caveolin-1 expression and PKA overactivation was inhibited by H89. CONCLUSION: Our results indicate that gentamicin induced caveolin-1 expression is mediated by PKA signaling pathway. We conclude that the caveolae/caveolin through a PKA signaling pathway is the important mechanism of gentamicin induced ototoxicity.