Gingko biloba extracts protect auditory hair cells from cisplatin-induced ototoxicity by inhibiting perturbation of gap junctional intercellular communication

Gap junctional intercellular communication (GJIC) may play an important role in the hearing process. Cisplatin is an anticancer drug that causes hearing loss and Gingko biloba extracts (EGb 761) have been used as an antioxidant and enhancer for GJIC. The purpose of this study was to examine the efficiency of EGb 761 in protecting against cisplatin-induced apoptosis and disturbance of GJIC. HEI-OC1 auditory cells were cultured and treated with cisplatin (50μM) and EGb (300μg/ml) for 24 h, and then analyzed by immunocytochemistry (Annexin V/ propidium iodide) and Western blots. The function of GJIC was evaluated by scrape-loading dye transfer (SLDT). Basal turn organ of Corti (oC) explants from neonatal (p3) rats were exposed to cisplatin (1–10μM) and EGb (50–400μg/ml). The number of intact hair cells was counted by co-labeling with phalloidin and MyoVIIa. EGb prevented cisplatin-induced apoptosis in immunostaining and decreased caspase 3 and poly-ADP- ribose polymerase (PARP) bands, which were increased in cisplatin-treated cells in Western blots. EGb prevented abnormal intracellular locations of Cx 26, 30, 31, and 43 in cells treated with cisplatin and increased quantities of Cx bands. EGb also prevented cisplatin-induced disturbance of GJIC in SLDT. In oC explants, EGb significantly prevented hair cell damage induced by cisplatin. In animal studies, EGb significantly prevented cisplatin-induced hearing loss across 16 kHz and 32 kHz. These results show that cisplatin induces ototoxicity including hearing loss as well as down-regulation of GJIC and inhibition of Cxs in auditory cells. EGb prevents hearing loss in cisplatin-treated rats by inhibiting down-regulation of Cx expression and GJIC. The disturbance of GJIC or Cx expression may be one of important mechanisms of cisplatin-induced ototoxicity.

Author dc:creator

• 최, 성준

Contributors dc:contributor

• 정, 연훈
• 대학원 의학과
• 105951

• Gap Junction
• Connexin
• Hearing loss
• Apoptosis
• Gingko biloba extracts
• Cisplatin

Language dc:language

en

Identifier

http://dcoll.ajou.ac.kr:9080/dcollection/jsp/common/DcLoOrgPer.jsp?sItemId=000000016585
000000016585

OAI identifier oai:identifier

oai:repository.ajou.ac.kr:201003/10920