γ-Synuclein在不同年龄段C57小鼠内毛细胞中的差异表达

Differential Expression Ofγ-Synuclein In Inner Hair Cells in C57 Mice at Different Ages

目的观察不同年龄段C57BL/6J小鼠内毛细胞中γ-Synuclein的表达差异性,探讨其与老年性聋听力损失的可能关系。方法随机选取出生后1月龄、3月龄、6月龄和9月龄C57BL/6 J小鼠各12只,对其进行ABR检测,取其耳蜗基底膜顶、底回进行免疫荧光染色,观察γ-Synuclein的表达差异情况。结果各年龄段C57小鼠ABR32kHz(高频)听力阈值分别为38.75±7.42、45.00±7.39、66.25±9.80、79.58±8.38dB SPL,从6月龄开始32kHz听阈明显升高(P<0.05),9月龄时相比6月龄进一步升高(P<0.05)。各年龄组免疫荧光染色耳蜗顶回γ-Synuclein染色完整未见缺失,底回γ-Synuclein出现选择性表达缺失,各年龄组选择性表达缺失数分别为1.08±1.00、1.25±1.22、2.75±1.91、4.42±2.11个,从6月龄开始γ-Synuclein在底回选择性表达缺失明显增加(P<0.05),9月龄时相比6月龄进一步增加(P<0.05)。结论γ-Synuclein选择性表达缺失增加的变化趋势与ABR测听高频听阈升高的变化趋势相符,提示γ-Synuclein与老年性聋听力损失存在可能关系。

Objective To report difference of expression ofγ-Synuclein in inner hair cells of C57BL/6J mice at different ages,to determine possible relationship betweenγ-Synuclein and presbycusis.Methods C57BL/6J mice at age of 1 month,3 months,6 months or 9 months(n=12 each)were randomly selected.ABR thresholds were obtained before harvesting the apical and basal turns of the cochlea to examineγ-Synuclein expression using immunofluorescence staining.Results ABR threshold at 32 kHz at 1,3,6 and 9 months were 38.75±7.42,45.00±7.39,66.25±9.80 and 79.58±8.38dB SPL,respectively,showing a significant threshold increase after 6 months of age(P<0.05),which continues at 9months(P<0.05).There was no loss ofγ-Synuclein staining in the apical turn in all age groups.Selective loss ofγ-Synuclein expression was seen in the basal turn at 1.08±1.00,1.25±1.22,2.75±1.91 and 4.42±2.11 for the 1,3,6 and 9months groups,respectively,again showing a significant increase after 6 months(P<0.05)that continued on at 9 months(P<0.05).Conclusion The increasing selective loss ofγ-Synuclein expression in the basal turn co-exists with elevation of high-frequency ABR threshold in aging mice,suggesting a possible relationship betweenγ-Synuclein and presbycusis.