经完整圆窗膜途径EGFP基因在大鼠耳蜗中的表达

Cochlear EGFP Gene Expression through an Intact Round Window Membrane in Rat

目的 研究经完整圆窗膜途径进行耳蜗基因转导的可行性及安全性 ,为内耳基因治疗提供实验基础和理论依据。方法 2 4只SD大鼠术前及术后分别行听性脑干反应 (ABR)检查。实验组 ( 18只 )用阳离子脂质体携带的增强型绿色荧光蛋白 (enhancedgreenfluorescentprotein ,EGFP)基因 ,对照组 ( 6只 )用生理盐水 ,注入置于圆窗龛处的明胶海绵内。分别于术后 3、7、14天取双侧耳蜗标本做基底膜铺片观察。结果 于圆窗龛处放置明胶海绵的转导方法对听力无明显影响。转染耳蜗呈明显的绿色荧光。 3天组表达产物最高 ,7天组逐渐降低 ,14天组更弱。对侧及对照组耳蜗均未见荧光表达。结论 于圆窗龛处放置明胶海绵进行基因转导的方法对听力没有影响 ,且能够成功转染耳蜗组织 。

Objective To observe the expression of cationic liposome mediated EGFP gene into the rat cochlea through an intact RWM, and to assess the effect of the operation on hearing.Methods Twenty-four adult SD rats were used for the study: eighteen were implanted with gelatin sponge soaked with cationic liposome-EGFP in the bony groove of the round window niche, six were implanted with gelatin sponge soaked with normal saline. Auditory brainstem response (ABR) thresholds were determined in all animals before and after surgery. On postoperative day 3, day 7 and day 14, the animals were sacrificed and the stretched preparation of cochleae were observed.Results ABR measurement showed that the operation had no significant effect on the ABR thresholds. Bright green fluorescence in the cochleae was observed in test groups. Gene expression was in the highest level three days after operation and reduced thereafter. However, the contralateral cochleae and control groups were free of fluorescence.Conclusion The technique of transgene delivery into the inner ear through an intact RWM is feasible, atraumatic and effective.