摘要
目的研究L型钙离子通道蛋白α1D亚基（Cav1．3）在老年性耳聋小鼠耳蜗组织中的表达和意义。方法应用听性脑干反应（ABR）分别检测4、14、24、48周龄的C57BL／6小鼠的听力，苏木素-伊红（HE）染色观察内耳形态的变化。免疫荧光方法观察Cav 1．3在内耳组织中的分布，同时采用反转录聚合酶链反应（RT—PCR）检测其基因CACNA1D在内耳组织的mRNA表达。结果Cav 1．3主要分布在小鼠耳蜗内外毛细胞、螺旋神经节、螺旋韧带、血管纹、螺旋（板）缘细胞。与4周龄小鼠比较，[短声（27．08±9．19）dBSPL、4KHz（23．79±13．31）dBSPL、8KHz（18．83±12．18）dBSPL3，14、24、48周龄ABR反应阈值提高（F=95．86，P〈0．05）；48周龄小鼠ABR反应阈值[短声（87．81±8．36）dBSPL、4KHz（85．63±9．88）dBSPL、8KHz（79．50±9．83）dBSPL3，较4、14、24周龄大鼠均提高（F=115．97，P％0．01）。随着鼠龄的增长，内耳毛细胞和螺旋神经节细胞逐渐出现缺失；血管纹和螺旋韧带也呈现萎缩；Cav 1．3表达含量逐渐减少，4周218．94±11．29，14周184．67±11．92，24周148．18±8．35与48周98．04±4．52比较，差异有统计学意义（F=119．17，P〈0．01）。结论老年性耳聋小鼠Cav 1．3钙离子通道蛋白表达含量随年龄增长而减少，其功能的异常和缺失可能在老年性耳聋的发病中起一定作用。
Objective To investigate the expression ofα1D subunit of L-type calcium channels （Cav 1. 3） in C57BL/6 mice cochlea and its correlation with presbycusis. Methods Auditory function was measured with auditory brainstem response（ABR） in C57BL/6 mice at 4, 14, 24 and 48 weeks. Morphological changes of the inner ear were studied by using hematoxylin and eosin staining. The expression of Cav1. 3 channels was detected by immunofluorescence and the expression of CACNA1D mRNA was determined by reverse transcription-polymerase chain reaction （RT-PCR）. Results Immunofluorescence photographs revealed that Cav1. 3 channels were mainly localized in the hair cell, spiral ganglion cell, spiral ligment, stria vascularis, spiral limbus. The ABR threshold at click（27.08±9.19） dB SPL, 4 KHz（23.79± 13.31）dB SPL, 8 KHz（18.83± 12.18）dB SPL, was higher in 14-, 24-, and 48-week group than in 4-week group （all P〈0.05）. The ABR threshold at click（87. 81± 8. 36） dB SPL, 4KHz（85. 63± 9. 88） dB SPL, 8KHz（79.50±9.83） dB SPL, was significantly higher in 48-week group than in 4-, 14-, 24-week groups （all P〈0.01）. Along with aging, the missing hair cells and spiral ganglion ceils were increased, stria vascularis and spiral ligament were atrophied in a certain degree, and the expression of Cavl. 3 channels was gradually decreased （4 weeks 218.94± 11.29; 14 weeks 184.67± 11.92; 24 weeks 148.18±8.35; 48 weeks 98.04±4. 523 all P〈0.01）. Conclusions The expression of Cavl. 3 channels is decreased along with age. Dysfunction or missing of Cavl. 3 calcium channels may be related to presbycusis.
出处
《中华老年医学杂志》
CAS
CSCD
北大核心
2014年第4期420-423,共4页
Chinese Journal of Geriatrics
基金
国家自然科学基金资助（81070787、81271078、30672307）
关键词
听觉丧失
钙通道
L型
毛细胞
听觉
Hearing loss；Calcium channels,L-type；Hair cell,auditory
