大鼠背根神经节持续压迫后miRNA差异表达谱的分析及功能研究

Differential expression profile and functional study of miRNA after chronic dorsal root ganglion compression in rats

目的:对大鼠背根神经节(dorsal root ganglion,DRG)持续压迫后所致神经病理性疼痛(neuropathic pain,NP)模型的DRG组织进行miRNA测序,应用生物信息学技术分析差异表达的miRNA及其靶基因在疾病中的定位与功能。方法:采用随机分组法将大鼠分为2组,每组12只,分别为假手术组、CCD背根神经节持续压迫(chronic compression of the dorsal root ganglion,CCD)模型组,术后进行行为学检测。确定痛觉敏感的天数后重复造模,取材后进行miRNA转录组测序。利用生物信息学手段筛选具有显著性差异的miRNA,预测相关靶基因并对其GO功能及KEGG富集情况进行分析,使用在线数据库对miRNA与靶基因之间的属性关系建立miRNA-靶基因的调控网络。最后,通过qPCR验证差异最为显著的4条miRNA在CCD模型DRG组织中的表达情况。结果:CCD造模7天后,大鼠痛觉最为敏感。重复造模,在第7天取材并进行miRNA转录组测序。将差异表达的miRNA以|log2(fold change)|>1且P<0.05为阈值,筛选符合要求的miRNA,与假手术组相比,有57种miRNA在CCD模型组表达上调,有17种miRNA在CCD模型组表达下调。差异表达的miRNA对应的靶基因主要富集在外泌体、细胞质、细胞膜、线粒体、内质网等结构,在细胞固有免疫、炎症信号传导、氧化应激等生物学过程中发挥重要作用,在PI3K-AKT、MAPK、JAK-STAT、钙信号等通路上均存在富集。经实验验证,miR-21-3p、miR-675-5p、miR487b-5p、miR-3585-3p的表达与测序结果一致。结论:在大鼠背根神经节慢性压迫所致NP模型的DRG组织中,异常表达的miRNA及其富集的相关信号通路可为NP诊断和治疗的新靶点提供新的思路。

Objective:MiRNA of the dorsal root ganglion(DRG)tissue in a neuropathic pain(NP)model caused by chronic compression of DRG was sequenced and bioinformatics techniques were used to analyze the location and function of differentially expressed miRNAs and their target genes in diseases.Method:Rats were randomly divided into 2 groups,12 rats in each group,including sham operation group and chronic compression of the dorsal root ganglion(CCD)model group.After identifying the days of pain sensitivity,the model was repeated,and miRNA transcriptome sequencing was performed after sampling.Bioinformatics methods were used to screen miRNAs with significant differences,predict related target genes,and analyze their GO function and KEGG enrichment.An online database was used to establish the attribute relationship between miRNA and target genes and to establish a miRNA-target gene regulatory network.Finally,qPCR was used to verify the expression of the four miRNAs with the most significant differences in DRG tissues of CCD model.Result:After 7 days of CCD modeling,the rats were most sensitive to pain.The models were repeated,and the miRNA transcriptome was sequenced on day 7.The differentially expressed miRNAs were screened according to the threshold of|log2(a fold change)|>1 and P<0.05.Compared with the control group,there were 57 kinds of miRNAs expression in the CCD model group,there were 17 kinds of miRNAs expressed in CCD model group.The target genes corresponding to differentially expressed miRNAs were mainly enriched in exosomes,cytoplasm,cell membranes,mitochondria,endoplasmic reticulum and other structures,which played important roles in cellular innate immunity,inflammatory signal transduction,oxidative stress and other biological processes,and were enriched in PI3K-AKT,MAPK,JAK-Stat,calcium signaling and other pathways.The experimental results also showed the expressions of miR-21-3p,miR-675-5p,miR-487b-5p and miR-3585-3p were consistent with the sequencing results.Conclusion:In the DRG tissue of NP model induced by chronic compression of rat dorsal root ganglion,the abnormally expressed miRNA and its enrichment related signaling pathway can provide new ideas for the diagnosis and treatment of NP.