甘草水提物中miRNA对人免疫细胞基因表达的影响

Effect of miRNA from Glycyrrhiza uralensis decoction on gene expression of human immune cells

微小RNA(micro RNA,miRNA)是一类在转录后水平调节基因表达的非编码小分子RNA,其调控基因表达、影响细胞活性的功能已为人们所重视。近年来miRNA的跨界调控成为新的研究方向,为人们更全面地认识和了解miRNA的功能提供了新的视角。植物miRNA由于通常经过了甲基化修饰,因此较为稳定,不易降解。前期研究表明,甘草干燥药材的水煎剂中存在着丰富的小分子RNA,这为了解甘草的作用机制提供了新的思路。在本研究中,利用从甘草水煎剂中提取的小分子RNA以及合成的miRNA模拟物(mimic)作用于分离自健康人的外周血单核细胞(peripheral blood mononuclear cell,PBMC),然后利用RT-PCR对其模式识别受体(PRR)基因以及部分转录因子、信号分子和细胞因子的基因表达变化进行了分析。结果表明甘草miRNA对人免疫细胞的基因表达具有明显的调节作用,能够显著抑制T细胞分化相关基因的表达,以及炎症和凋亡相关基因的表达。这为进一步更全面地了解甘草的作用机制以及中药新药的研制带来了新的思路。

MicroRNAs（ miRNA） are small non-coding RNAs that regulate the expression of protein coding genes by repressing translation of protein coding mRNA or enhancing mRNA degradation. Its functions have attracted more and more attention from the public. In recent years,the cross-border regulation of miRNA has become a new research direction,and provides a new perspective for people to comprehensively understand the functions of miRNA. Plant miRNA is usually methylated and not easy to degrade. According to our previous researches,there were abundant small RNAs in the decoction of dried liquorice,which provides a new way to study the mechanism of action of licorice. In this study,small RNAs extracted from Glycyrrhiza uralensis decoction and synthesized miRNA mimics were used to treat peripheral blood mononuclear cells（ PBMC） isolated from healthy volunteers. The gene expression of toll-like receptors（ TLRs）,some transcription factors,signal molecules and cytokines were analyzed by RT-PCR. The results showed that glycyrrhiza miRNA could significantly regulate PBMC by inhibiting the expression of genes involved in T cell differentiation,inflammation and apoptosis. The study brought new ideas to us in comprehensively studying the mechanism of licorice and developing the traditional Chinese medicine.