Skp2在年龄相关性听力损失小鼠耳蜗中的表达

The Expression of Skp2 in the Cochlea of Age-related Hearing Loss Mice

目的探讨年龄相关性听力损失(ARHL)小鼠耳蜗中S期激酶相关蛋白-2(Skp2)的表达及作用。方法63只健康的1月龄C57BL/6J雄性小鼠随机分为2月龄组、8月龄组和12月龄组,每组21只,饲养至相应月龄。各组小鼠行听性脑干反应(ABR)检测,并测试各组小鼠耳蜗丙二醛(MDA)水平和总超氧化歧化酶(T-SOD)活力,显微镜下计数基底膜毛细胞缺失,免疫荧光染色及Western blot观察耳蜗中Skp2水平变化。结果与2月龄组相比,8月龄组和12月龄组小鼠8~32 kHz各频率ABR阈值、耳蜗中MDA水平及毛细胞缺失率均明显升高(均为P<0.01),耳蜗中T-SOD活力和Skp2蛋白水平显著降低(均为P<0.01);且上述检测指标在12月龄组小鼠的变化最为显著。结论随着ARHL小鼠年龄的增长,Skp2表达水平逐渐降低,Skp2的减少可能与ARHL发展有关。

Objective To investigate the expression of S-phase kinase-associated protein-2(Skp2)in the co chlea of mice with age-related hearing loss(ARHL)and to explore the potential relationship between Skp2 and ARHL.Methods Sixty-three healthy C57BL/6J male mice at 1-month-old were randomly divided into the following 3 groups the 2-month-old group,8-month-old group and 12-month-old group(21 mice/group)and fed to the corresponding month age.The hearing function was detected by auditory brainstem response(ABR).The level of malondialdehyde(MDA)and the activity of total superoxide dismutase(T-SOD)were measured to evaluate the level of oxidative stress in the cochlea of mice.The loss of basal membrane hair cells was observed under a microscope,and the expression of skp2 in the cochlea were detected by immunofluorescence and Western blot.Results Compared with the 2-month-old group,8-month-old group and 12-month-old group showed significant increase in ABR from 8~32 kHz(P<0.01),MDA level in the cochlea(P<0.05),and the percentage of cochlea hair cell loss were increased(P<0.05),with significant decrease in T-SOD activation and Skp2 protein expresion(P<0.01).Additionally,the changes of the above-mentioned dection indeves were the most significant in 12-month-old group.Conclusion In ARHL mouse,the expression of Skp2 gradually decreased with the increse of age.The decrease of Skp2 may be related to the development of ARHL.