唐氏综合征胎盘差异miRNA表达谱分析:基于全转录组测序分析技术

Whole-transcriptome sequencing analysis of placental differential miRNA expression profile in Down syndrome

目的通过筛选唐氏综合征胎盘中表达变化的miRNAs并分析具体生物学途径来探讨唐氏综合征新的标记物及其分子发病机制。方法运用全转录组测序分析技术分析唐氏综合征确诊胎盘(DS,n=3)和产前诊断确诊正常胎盘(n=3)样本,筛选出显著差异表达的miRNA,通过miRWalk、Targetscan、miRDB软件预测其靶基因并进行GO和KEGG-Pathway功能富集分析。结果测序分析共检出82个差异表达的miRNA。DS胎盘组织中有29个miRNA表达上调(变化倍数≥2,P<0.05),15个miRNA表达下调(变化倍数≥2,P<0.05);根据表达丰度共筛选出4个表达上调的miRNA,6个表达下调的miRNA。其共同靶基因BTBD3、AUTS2均与神经发育相关。GO富集分析结果显示差异表达miRNA的靶基因主要富集到蛋白结合、水解酶活性、金属离子结合、转移酶活性、核苷酸结合、胞质组分、细胞核组分、转录调控、RNA代谢过程调控、DNA依赖性RNA聚合酶Ⅱ启动子转录调控、眼睛发育、感觉器官发育等。KEGG富集分析结果显示差异表达miRNA靶基因主要参与的信号通路包括肿瘤相关信号通路、PI3K-Akt信号通路、Ras信号通路、Rap1信号通路、细胞骨架调控信号通路、嘌呤代谢相关信号通路、P53相关信号通路。结论miRNAs可能参与了唐氏综合征胎盘损伤和相关的妊娠病理,并可能对其他智力障碍相关疾病提供一定临床思路及对未来的预防治疗发挥重要作用。

Objective To identify new biomarkers and molecular pathogenesis of Down syndrome(DS)by analyzing differentially expressed miRNAs in the placentas and their biological pathways.Methods Whole transcriptome sequencing was used to identify the differentially expressed miRNAs in DS(n=3)and normal placental samples(n=3)diagnosed by prenatal diagnosis.The target genes were predicted using miRWalk,Targetscan and miRDB,and GO and KEGG pathway analyses were performed for gene enrichment studies.Results We identified a total of 82 differentially expressed miRNAs in the placental tissues of DS,including 29 up-regulated miRNAs(fold change≥2,P<0.05)and 15 down-regulated miRNAs(fold change≥2,P<0.05),among which 10 miRNAs with relatively high expression abundance were selected for further analysis,including 4 up-regulated and 6 down-regulated miRNAs.These selected miRNAs shared the common target genes BTBD3 and AUTS2,both of which were associated with neurodevelopment.GO analysis showed that the target genes of the selected miRNAs were mainly enriched in protein binding,hydrolytic enzymes,metal ion binding protein combining,transferase activity,nucleotide,cytoplasmic constituents,nucleus composition,transcriptional regulation,RNA metabolism regulation,DNA-dependent RNA polymerase II promoter transcriptional regulation,eye development,and sensory organ development.KEGG enrichment analysis showed that the target genes of these differentially expressed miRNAs were involved in the signaling pathways including tumor-related signaling pathway,PI3K-Akt signaling pathway,Ras signaling pathway,Rap1 signaling pathway,cytoskeletal regulatory signaling pathway,purine metabolization-related signaling pathway and P53signaling pathway.Conclusion The differentially expressed miRNAs may play important roles in placental damage and pregnancy pathology in DS and provide clues for the prevention and treatment of mental retardation-related diseases.