神经营养因子3基因转染对庆大霉素性耳聋保护作用的实验研究

Protection of NT3 gene transfection on the guinea pig cochlea treated with gentamicin

目的 :探讨阳离子脂质体介导的神经营养因子 3(NT3)基因转染对豚鼠庆大霉素性耳聋的保护作用。方法 :将携带外源性基因NT3的重组真核表达载体 pIRES2 EGFP NT3与阳离子脂质体复合物注入豚鼠耳蜗 ,术后给予庆大霉素肌肉注射 (12 0mg/kg) 14d ,分别于停药后 1d、2周进行听性脑干反应 (ABR)及畸变产物耳声发射 (DPOAE)测听并观察转染基因在耳蜗的表达和分布及耳蜗毛细胞受损情况。结果 :NT3组DP gram幅值降低较对照组明显减轻 ,ABR阈值升高亦无对照组显著 (P <0 .0 5 )。耳蜗基底膜FITC phalloidin染色见NT3组耳蜗毛细胞的缺失较对照组明显减轻。结论 :阳离子脂质体介导的NT3基因转染对豚鼠庆大霉素性耳聋具有一定程度的保护作用。

Objective:To study the protection of NT3 gene transfection on the guinea pig cochlea treated with gentamicin.Method:The liposome -plasmid complex (pIRES2-EGFP-NT3) was injected into the guinea pig cochlea, then the guinea pigs were treated with gentamicin (120 mg/kg, 14 d). The DPOAE and ABR were measured at 1 d and 2 w after stop the genetamicin and the expression of NT-3 was observed respectively,and the hair cells were observed.Result:Compared with the group of NT3, the DPOAE of the guinea pigs transfected with blank vector and PBS were evidently dropped (P< 0.05 ).The ABR thresholds were similar with the results of DPOAE.The hair cells with the FITC-phalloidin immunohistochemical dyeing showed that the absence of hair cells in the groups of NT3 were little severity than the compared groups.Conclusion:This study showed that cochlear NT3 gene transfection could provide safe and effective production to the guinea pigs treated with gentamicin.