Progression of hair cell ejection and molecular markers of apoptosis in the avian cochlea following gentamicin treatment
Progression of hair cell ejection and molecular markers of apoptosis in the avian cochlea following gentamicin treatment
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DOI：
10.1002/cne.20129
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发表时间：
2004-07-12
影响因子：
2.5
通讯作者：
Cotanche, DA
中科院分区：
文献类型：
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作者：
Mangiardi, DA;McLaughlin-Williamson, K;Cotanche, DA
氨基糖苷处理诱导内耳感觉毛细胞caspase依赖性凋亡死亡。在全身氨基糖苷治疗后，感觉毛细胞凋亡信号的时间尚未在体内表征。我们给12-16日龄的小鸡皮下注射氨基糖苷庆大霉素（300 mg/kg），并使用免疫细胞化学技术记录了受影响毛细胞的以下反应：t细胞限制了细胞内抗原相关蛋白（TIAR）从细胞核向细胞质的易位、线粒体细胞色素c的释放、caspase-3激活、核凝聚以及基底乳头近端毛细胞抛射的有序进展。注射后12小时，近端毛细胞发生TIAR移位，并在细胞质中聚集成点状颗粒，反应向远端进展。细胞色素c从线粒体释放到细胞质中，caspase-3在受影响的毛细胞中被激活。毛细胞射出发生在注射后30至54小时，从尖端近端开始，向远端发展。核冷凝伴随着喷射，同时膜完整性的丧失；2) f -肌动蛋白的phalloidin标记；3)在抛射后48小时内对核内容物进行TO-PRO-1标记。我们的研究结果给出了氨基糖苷诱导的内耳感觉毛细胞凋亡的时间轴，包括从最初的凋亡反应到伴随射血的程序性死亡信号的后期阶段以及射血后毛细胞的逐渐分解之间的18小时窗口。(C) 2004 Wiley-Liss, Inc。
Aminoglycoside treatment induces caspase-dependent apoptotic death in inner ear sensory hair cells. The timing of apoptotic signaling in sensory hair cells following systemic aminoglycoside treatment has not been characterized in vivo. We administered a single subcutaneous injection of the aminoglycoside gentamicin (300 mg/kg) to 12-16-day-old chicks and used immunocytochemical techniques to document the following responses in affected hair cells: T-cell restricted intracellular antigen-related protein (TIAR) translocation from the nucleus to the cytoplasm, cytochrome c release from the mitochondria, caspase-3 activation, nuclear condensation, and an orderly progression of hair cell ejection from the proximal end of the basilar papilla. Hair cells in the proximal tip exhibited TIAR translocation from the nucleus and aggregation into punctate granules in the cytoplasm 12 hours after injection and the response progressed distally. Cytochrome c release from the mitochondria into the cytoplasm and caspase-3 activation were observed in affected hair cells immediately prior to and during ejection. Hair cell ejection occurred between 30 and 54 hours after injection, beginning in the proximal tip and progressing distally. Nuclear condensation accompanied ejection while the loss of: 1) membrane integrity; 2) phalloidin labeling of F-actin; and 3) TO-PRO-1 labeling of nuclear contents occurred within 48 hours following ejection. Our results present a timeline of aminoglycoside-induced inner ear sensory hair cell apoptotic death that includes an 18-hour window between the initial apoptotic response and the later stages of programmed death signaling that accompany ejection and a gradual breakdown of hair cells following ejection. (C) 2004 Wiley-Liss, Inc.