摘要
目的观察Smad5基因敲除小鼠(Smad5+/-)听生理和耳蜗形态改变,探讨Smad5基因是否为一种新的听功能相关基因。方法双盲对照法对Smad5(+/-)和Smad5(+/+)小鼠进行听性脑干诱发电位(ABRs)的听阈检测和耳蜗毛细胞形态观察及毛细胞计数。结果ABR听阈Smad5(+/-)小鼠24周时为90.63±17.65dB(SPL),Smad5(+/+)小鼠为63±19.94dB(SPL),二者差异显著(P<0.01)。耳蜗基底膜铺片显示Smad5(+/-)小鼠内、外毛细胞缺失,其中在底回处尤其突出,Smad5(+/+)小鼠内、外毛细胞少量缺失。Smad5(+/-)与Smad5(+/+)小鼠外毛细胞计数差异有显著性意义(P<0.01),而内毛细胞计数差异无显著意义(P>0.05)。结论Smad5基因敲除导致小鼠中、重度听力下降,耳蜗基底膜毛细胞缺失,以外毛细胞为主。Smad5基因敲除导致毛细胞缺失是Smad5(+/-)小鼠听力损失的原因之一。推测Smad5基因可能是听功能相关基因。
Objective To observe the Smad5 gene knockout and induced-changes of auditory physiology and cochlea morphology in mouse, to explore whether Smad5 gene is a new gene related to hearing function. Methods Double blind control methods were used to detect the auditory threshold of auditory brainstem responses (ABR) in the mouse of Smad5 (+/+) to Smad5(+/-) and the cochlea morphology (cochlea paraffin-cut section and basal membrane spreading section). The hair cell count was also taken. Results As shown by ABR audiometry, the average hearing of Smad5 (+/-) mouse (aged 24 weeks) is 90.63±17.65 dB (SPL) and that of Smad5(+/+) mouse is 63±19.94 dB(SPL), which are of significant difference (P<0.01). As shown by cochlea basal membrane spreading section, both internal and external hair cells became deficient in Smad5 (+/-) mouse (especially in its basal turn) but only slightly deficient in Smad5 (+/+) mouse. The comparison of external hair cell count between Smad5 (+/-) and Smad5 (+/+) mice indicated a significant difference (P<0.01). However, the comparison of internal hair cell count between Smad5 (+/-) and Smad5 (+/+) mice indicated no significant difference (P>0.05). Conclusion Smad5(+/-) gene knockout can cause the mouse a auditory threshold decline in moderate or severe extent. Cochlea morphology indicated that hair cells (mainly outer hair cells) in mouse cochlea basal membrane became deficient. A mechanism of Smad5 gene knockout to caused the deafness and the deficiency of hair cells remained to be further studied.
出处
《解放军医学杂志》
CAS
CSCD
北大核心
2005年第7期579-581,共3页
Medical Journal of Chinese People's Liberation Army
基金
国家自然科学基金(编号30000189)
军队"十五"医药卫生科研基金(编号01Q050)
北京市自然科学基金(编号7042061)资助课题
