MicroRNA在新生和老年大鼠内耳表达差异的分析*

目的观察新生大鼠和老年大鼠内耳基底膜中microRNA(miRNA)的表达差异,探索与老年性聋有关的miRNA.方法取新生大鼠基底膜和老年大鼠基底膜各8只,提取miRNA,采用探针法进行两组大鼠miRNA的差异分析.结果用Two Class Diff法检测可发现18种差异性表达的miRNA,其中有16种miRNA在老年大鼠中表达高于新生大鼠,增长的倍数为17~600倍不等;2种miRNA在老年大鼠中表达下降,他们分别是rno-miR-29c和rno-miR-29a.结论 microRNA的变化早于耳蜗形态和功能的老化,microRNA表达的上调和下调与老年性聋有关.

The Differences of MicroRNA Expressions in the Organ of Corti between Neonatal and Aging Rats

Objective To observe the microRNA（miRNA） expressions in the organs of Corti of neonatal and aging rats, and to find which miRNAs are involved in age-related degeneration of the organs of Corti. Methods The organs of Corti were isolated from the neonatal and aging rats and the microRNAs were extracted. The TaqMan microRNA Assay was used to compare the difference of miRNA expressions between the two groups. Results A total of 18 miRNAs exhibited different expressions in the aging rat cochleae when compared with the newborn rat cochleae. Among these miRNAs, 16 miRNAs were upregulated in aging rats with the fold changes ranging from 17 to 600 folds. The expression levels of two miRNAs （rno-miR-29c and rno-miR-29a） were reduced in the aging rat cochleae. Conclusion The changes in miRNA expressions precede morphological and functional changes, and the upregulation of pro-apoptotic miRNAs and downregulation of miRNAs were involved in age-related cochlear degeneration.