阿米卡星对小鼠内耳水通道蛋白4表达的影响

Effect of Amikacin on Aquaporin 4 Expression in Mice Inner Ear

目的观察阿米卡星对小鼠内耳水通道蛋白4(aquaporin 4,AQP4)表达的影响,探讨AQP4在阿米卡星耳毒性机制中的可能作用。方法 60只CBA/CaJ小鼠随机分为实验组和对照组,每组30只,实验组小鼠皮下注射阿米卡星450mg·kg-1·d-1,每天1次,共14d,对照组小鼠皮下注射等量生理盐水。注射4天后应用免疫组化染色分别检测两组小鼠耳蜗AQP4的表达及定位情况,应用蛋白免疫印迹技术及RT-PCR技术检测两组小鼠内耳AQP4表达水平的变化。结果 AQP4在小鼠内耳表达于Corti器的支持细胞。对照组和实验组的AQP4蛋白相对含量分别为0.672±0.074、0.479±0.108,AQP4mRNA相对含量分别为0.701±0.107、0.460±0.080,实验组AQP4的蛋白及mRNA的相对含量均低于对照组,差异有统计学意义(P<0.01)。结论阿米卡星可导致小鼠内耳AQP4蛋白及基因表达的下调,这可能是阿米卡星耳毒性的机制之一。

Objective To study the effect of amikacin on aquaporin 4 （AQP4） expression in mice inner ear and reveal the possible mechanism of amikacin ototoxicity. Methods A total of 60 CBA/CaJ mice were randomly di- vided into experimental group and control group with 30 mice in each group. Experimental group mice were subcuta- neously injected with 450 mg/kg amikacin once a day for 2 weeks,meanwhile control group mice were injected with normal saline. The expression of AQP4 were detected by immunohistochemistry. The changes of AQP4 protein and mRNA abundance were detected separately by Westen Blots and RT--PCR. Results AQP4 in mice inner ear mainly located in supported cells in Corti＇s organ. AQP4 protein abundance in experimental group and control group were 0.672±0.074 and 0.479±0.108, mRNA abundance were 0.701±0.107 and 0.460±0.080, respectively. The a- bundance of AQP4 protein and mRNA in inner ear in amikacin-treated mice were significantly lower than those of in control group. Oonclusion Amikacin may down--regulate AQP4 expression in mice inner ear.