Nuclear translocation of the pro-apoptotic protein BNIP3 in cultured spiral ganglion cells of rat with cisplatin insult
10.3760/cma.j.issn.1673-0860.2011.03.010
- VernacularTitle:顺铂诱导大鼠体外培养耳蜗螺旋神经节细胞凋亡中BNIP3的核转位表达
- Author:
Ping WANG
1
;
Yong TANG
;
Xia CHEN
;
Bo DU
Author Information
1. 吉林大学第一医院
- Keywords:
Cochlea;
Spiral ganglion;
Cisplatin;
Apoptosis;
Membrane proteins;
Genes,bcl-2
- From:
Chinese Journal of Otorhinolaryngology Head and Neck Surgery
2011;46(3):214-219
- CountryChina
- Language:Chinese
-
Abstract:
Objective To observe spiral ganglion cell(SGC) death pattern caused by cisplatin and investigate pro-apoptotic protein BNIP3 involve ment in SGC death. Methods Cochlear SGC were isolated from the neonatal rats and cultured in vitro. A cochleas insult model were induced by treatment of 100 μmol/L cisplatin. Real-time PCR were used to determine expression of apoptosis related gene in neonatal rat cochlear cultures after cisplatin treatment. Western blotting was used to detect α-spectrin and indirectly determine caspase-3 activity. Double immunohischemical staining method was performed to indicated the localization and expression of BNIP3 and NF-200. Results Morphological finding showed that SGC were smaller, and neurofiber were blebbing and broken at treatment of cisplatin for 12 h. NF-200marker positive cell number decreased. The transcription level of BNIP3 in cisplatin treatment for 3 h,6 h and 12 h was higher than the control group(P ＜0. 05). Western blotting results showed that 120 000 of breakdown products of α-spectrin relative gray level were 0. 10 ±0. 05 in the control group, 0. 49 ±0. 09 and 0. 75 ±0. 08 in cisplatin treatment for 6 h and 12 h group. It increased significantly in the group of cisplatin treatment for 6 h and 12 h than the control group (q =8. 63 and 14. 61 ,P ＜0. 01 ). When compared between 6 h of cisplatin treatment and 12 h group, significant difference was detected (q = 5.98 ,P ＜ 0. 05 ). There was weak BNIP3 positive expression in cytoplasm of the control group. However, strongly BNIP3-positive labeled were seen in the nucleus of SGC and cytoplasm of some stromal cells around SGC after cisplatin treatment. Conclusions BNIP3 played an important role in cisplatin induced SGC death and followed independent signaling transduction pathway that differ from stromal cells around SGC. It may suggest that BNIP3 enter nucleus to bind DNA and up-regulate apoptotic gene expression to promote cells death.
