Fund programs: National Natural Science Foundation of China(No.82360261);Digital Development and Application of Biological Resources Project [2022] of Kunming Medical University(No.202002AA100007);High-level Talent Support Program of Yunnan Province(Young Top Talent Special Project)(No.KYQY20210816);The Open Project of the Clinical Medical Center for Reproductive Gynecological Diseases of Yunnan Province(No.2022LCZXKF-SZ14)
Authors：Zhang Yaqin; Ma Zhongrui; Qian Yuan; Li Junjun; Deng Xingli
Keywords：Down syndrome; miRNA; sequencing; amniotic fluid; placenta;
DOI：10.19405/j.cnki.issn1000-1492.2025.06.024
〔Abstract〕 Objective To analyze the differential expression profile of miRNAs in amniotic fluid exosomes of fetu- ses with Down syndrome (DS) and provide insights for identifying novel biomarkers for the prenatal diagnosis of DS . Methods Amniotic fluid samples were collected from fetuses with DS and chromosomally normal fetuses . Exo- somes were isolated from the amniotic fluid and subjected to high-throughput sequencing. Differentially expressed miRNAs were identified , and target genes were predicted using TargetScan and miRanda. Target genes located on chromosome 21 were selected , and their biological functions and associated diseases were analyzed using Gene- Cards , HGNC , NCBI Gene , UniProtKB/Swiss-Prot , Ensembl , and OMIM databases . GO and KEGG enrichment analyses were performed to investigate the biological functions of the enriched genes . Results A total of 59 differ- entially expressed miRNAs were identified , including 31 upregulated and 28 downregulated miRNAs . Based on a fold change > 2 and P < 0. 05 , 10 upregulated and 9 downregulated miRNAs with the highest expression levels were selected . Key miRNAs included hsa-let-7b-5p , hsa-let-7c-5p , hsa-let-7b-3p _ 1ss22CT , and hsa-miR-199b-5p , with BACH1 and IFNAR1 identified as their shared target genes . GO analysis revealed that the enriched target genes were primarily involved in protein binding , metal ion binding , transferase activity , DNA binding , transcriptional regulation by RNA polymerase Ⅱ , and nucleotide binding. KEGG pathway analysis indicated that the target genes were mainly associated with metabolic pathways , cancer-related pathways , the PI3K-Akt signaling pathway , and the Rap1 signaling pathway . Conclusion Differential expression of miRNAs in amniotic fluid exosomes was ob- served between DS fetuses and those with normal karyotypes . Combined analysis with placental miRNAs revealed hsa-miR-199b-5p as a common differentially expressed miRNA in both DS amniotic fluid and placenta. It is hypoth- esized that BACH1 and IFNAR1 , shared target genes of hsa-miR-199b-5p , hsa-let-7b-5p , hsa-let-7c-5p , and hsa- let-7b-3p_1ss22CT , may play a role in the pathogenesis of DS .