稳态噪声性听神经损伤后耳蜗内人神经营养素-3基因重组腺病毒的表达与观察

Expression of NT3 Gene in the Cochlea After Intensive Noise Trauma in Guinea Pig

目的观察含有人神经营养素-3(human neurotrophin-3,hNT-3)的重组腺病毒(Ad-NT3)在稳态噪声性听神经损伤后耳蜗内的表达。方法30只听力正常豚鼠暴露于稳态强噪声(130 dB SPL×5 h),3天后经鼓阶外淋巴腔内导入目的基因,24只注射Ad-NT3,6只注射人工外淋巴液作为对照。分别于基因导入后第11、28、56天取材,用免疫组织化学染色方法观察Ad-NT3在耳蜗内的转染。结果基因导入后第11天可见Ad-NT3在耳蜗内成功转染,耳蜗各回均有表达,表达强度在各回基本相等;第28天仍可见Ad-NT3在耳蜗内表达,蜗轴区表达最强,但较第11天表达减弱;56天时未见表达。结论NT-3重组腺病毒能在稳态噪声性听神经损伤后耳蜗内实现高效表达,表达可以持续相当长时间。

Objective To observe the expression of recombined adenovirus with human neurotrophin- 3 cDNA （Ad- NT3） in guinea pig cochlea after intensive noise trauma. Mothods Thirty healthy guinea pigs were equally divided into three groups. All animals were exposed to stable intensive noise （ 130 dB SPL） for five hours. Three days after exposure, twenty- four animals were inoculation with Ad - NT3 into perilymphatic space, while the other six were introduced with aaJfical perilymphatic fluids（APF） as control. The animals were sacrafied at eleventh, twenty- eighth and fifty- sixth days separately, paraffin section of cochlea were made and observed with microscope. Immtmohistochemistry was used to detect the expression of NT3 protein in the cochlea.Results Ad - NT3 protein was expressed in each turn of the cochlea. The intensity was almost equal eleven days after inoculation. The reactive tissures included spiral limbns, spiral ligament and ganglion cells. At the twenty - eighth days, the reactive intensity reduced, while axis relatively stronger than the other tissues. There was no reaction at the fifty - sixth days. Conclusion Ad- NT3 can be expressed in the noise- injured cochlea for a relatively long time.