小鼠鼓室注射小干扰RNA导入内耳可行性研究

Delivery of Short Interfering RNA Through Otic Bone Into Mouse Cochlea

目的探讨将小干扰RNA经鼓室注射导入小鼠内耳的可行性。方法选取三月龄健康小鼠,经鼓室注射荧光标记的小干扰RNA探针以及热休克蛋白70(HSP70)小干扰RNA,三日后经耳蜗冰冻切片及基底膜铺片,检测小干扰RNA进入内耳情况及外毛细胞中HSP70蛋白表达。结果鼓室注射荧光标记的小干扰RNA探针三日即可被成功导入耳蜗组织,鼓室注射HSP70 siRNA可抑制毛细胞内HSP70表达,与对照组相比有显著差异(p<0.01)。结论小鼠鼓室注射小干扰RNA是一种有效的将小干扰RNA导入内耳尤其是毛细胞的方法,在毛细胞损伤机制研究中有一定应用价值。

Objective To investigate the advantages of the method of intra-tympanic injection through the otic bone for the delivery of siRNA into the adult mouse cochlea. Methods A fluorescently-conjugated scrambled siRNA probe was ap- plied via intra-tympanic injection into the middle ear cavity to detect if the siRNA probe could be delivered into organ of corti and HSP70 siRNA was delivered into cochlea to reduce the expression of HSPT0 in hair cells. Results Fluorescently-eonjugat- ed scrambled siRNA probe was detected in sensory hair cells and nerve fibers 3 days after the injection. Intra-tympanic deliv- ery of HSP70 siRNA successfully reduced immunofluorescence associated with HSP70 in outer hair cells 3 days after injection. Conclusion Intra-tympanic injection through the otic bone into the middle ear cavity provides a promising approach for delivery of compounds or siRNA to cochlear hair cells of mice, relevant for the study of mechanisms underlying inner ear insults.