Effect of Inositol-requiring Enzyme 1 on Cisplatin-induced Apoptosis of Cochlear Hair Cells in Mouse / 听力学及言语疾病杂志

ABSTRACT

Objective To investigate the effect of inositol-requiring enzyme 1(IRE1)on cisplatin-induced ap-optosis of cochlear hair cells in mouse.Methods The cochlear basilar membranes of 500 healthy Kunming mice(3～5 days old)were isolated and cultured in vitro.After 24 hours,they were randomly divided into control group and cisplatin groups(4 μg/ml,8 μg/ml,16 μg/ml and 32 μg/ml),and cultured for another 24 hours.The loss of co-chlear hair cells was observed by fluorescein isothiocyanate(FITC)staining.The apoptosis of cochlear hair cells was observed by TRITC and Hoechst 33258 fluorescence staining.Western blot was used to detect the protein levels of p-IRE1α,p-JNK,Bax and caspase-3 in each group.Results Compared with control group,the hair cell loss and apoptosis rate of hair cells and the protein levels of p-IRE1α,p-JNK,Bax and caspase-3 were significantly increased in cisplatin groups(P＜0.01).Furthermore,the expression of p-IRE1α was positively correlated with the expres-sion of Bax and caspase-3 and with the apoptosis rate of hair cells(P＜0.05).Conclusion IREI may be involved in the regulation of cisplatin-induced apoptosis in cochlear hair cells.