Identification of a microRNA regulator for axon guidance in the olfactory bulb of adult mice

Using the highly sensitive miRNA array, we screened 40 microRNAs abundant in the olfactory bulb and we explored the functions of these miRNAs in the olfactory bulb by Gene Ontology and Kyoto Encyclopedia of Genes annotation. The enrichment results indicated that these miRNAs mainly participated in the axon guidance process. Furthermore, the quantitative real-time polymerase chain reaction, immunohistochemistry, and dual luciferase reporter assay results showed that miR-30c is a specific regulator of semaphorin-3A, which will give new insights in disclosing the mechanism of functional maintenance and sexual-specific differentiation of the olfactory bulb. In this study, three samples from steady-state mice were used to acquire the miRNA expression profiling and the function of the abundant miRNAs in the olfactory bulb were analyzed by bioinformatic methods.Finally, miR-30c was experimentally validated to be a regulator of semaphorin-3A, an important axon guidance cue in the nervous system.本研究采用高灵敏度miRNA芯片（miRNA array），筛选出40种在嗅球中高表达的microRNA（miRNA），并通过基因本体（Gene Ontology）与京都基因注释百科全书（Kyoto Encyclopedia of Genes）注释分析，探究此类miRNA在嗅球中的生物学功能。富集分析结果显示，此类miRNA主要参与轴突导向过程。此外，实时定量聚合酶链式反应、免疫组织化学及双荧光素酶报告基因实验结果证实，miR-30c是信号素3A（semaphorin-3A）的特异性调控因子，该发现为揭示嗅球功能维持与性别特异性分化的分子机制提供了新的研究视角。本研究选取3份稳态小鼠样本获取miRNA表达谱，并通过生物信息学方法分析嗅球中高表达miRNA的功能。最终，实验验证miR-30c可作为神经系统中重要轴突导向信号分子信号素3A的调控因子。