目的 :筛选与不明原因复发性流产(unexplained recurrent spontaneous abortion,URSA)相关的微小RNA(miRNA),探讨其在URSA发生中的作用及其可能机制。方法:通过对URSA绒毛组织进行miRNAs测序,初步筛选差异表达的miRNAs;利用实时荧光定量PCR,验证筛选所得miRNAs表达水平;利用DAVID软件对靶基因进行Pathway分析;利用实时荧光定量PCR,检测p53通路中靶基因及其下游基因的表达水平。结果:let-7f-5p在URSA绒毛组织中表达水平显著上升;let-7f-5p的靶基因富集于p53通路,通路中靶基因MDM-X和其下游靶标促生长基因MDM2水平显著下降,促凋亡基因p53表达水平显著上升。结论:let-7f-5p可能调控p53信号通路中MDM-X/MDM2/p53基因,促进细胞凋亡,最终导致URSA发生发展。 Objective: To screen for microRNAs (miRNAs) associated with unexplained recurrent spontaneous abortion (URSA), and to explore its possible role in the pathogenesis of URSA. Methods: The miRNAs of URSA villi were sequenced to screen differentially expressed miRNAs. Real-time PCR was used to confirm the expression of miRNAs. Pathway analysis was performed on the target genes using DAVID software. Real-time fluorescence quantitative PCR was used to detect p53 pathway Target gene and its downstream gene expression levels. The expression of let-7f-5p was significantly increased in URSA villi. The target gene of let-7f-5p was enriched in the p53 pathway, and the target gene MDM-X and its downstream target gene MDM2 in the pathway were significantly decreased. The expression of pro-apoptotic gene p53 increased significantly. Conclusion: let-7f-5p may regulate the MDM-X / MDM2 / p53 gene in p53 signaling pathway and promote cell apoptosis, leading to the development of URSA.