Bioinformatics analysis and validation of differentially expressed miRNA in the sperm of partners of patients with unexplained recurrent miscarriages

BackgroundRecurrent miscarriage is a common multifactorial disease, and even after systematic examination, the cause of the miscarriages cannot be determined in approximately 50% of patients. However, currently, few examinations are conducted for partners of patients with recurrent miscarriages. The contribution of spermatozoa to new individuals is not limited to half of the diploid genome. Recent studies have shown that spermatozoa add several components to oocytes, including a complex RNA population that plays an important role in paternal chromatin packaging, sperm maturation and empowerment, fertilisation, early embryogenesis, and developmental maintenance. In view of this, we constructed a sperm miRNA expression profile of partners of patients with unexplained recurrent miscarriages and explored the relationship between unexplained recurrent miscarriages and differential miRNA expression in sperm. MethodsSemen samples were obtained from the partners of patients with unexplained recurrent miscarriages treated at the affiliated hospital of Inner Mongolia Medical University, as well as healthy men who underwent physical examinations between July 2021 and February 2023. The miRNA expression profiles of the sperm in the two groups were detected using high-throughput sequencing. Bioinformatics analysis of differentially expressed miRNAs was performed to predict target genes and their action pathways and verify the expression levels of paternal miRNAs in known embryos in the study and control groups through RT-PCR technology. ResultA total of 83 differentially expressed miRNAs were detected between the two groups, of which 39 were significantly upregulated and 44 were significantly downregulated. The results showed that spermatic hsa-miR-34c-5p, hsa-miR-1285-3p, hsa-miR-486-3p, and hsa-miR-146b-3p may regulate the occurrence of unexplained recurrence through the Ras, PI3K-Akt, and MAPK signalling pathways in the bioinformatics analysis. The expression of hsa-miR-34c-5 in spouses of patients with unexplained miscarriage recurrence was downregulated (p < 0.001). Binary logistic regression analysis showed that low expression of hsa-miR-34c-5p was a high-risk factor for recurrent miscarriage (odds ratio [OR] = 4.344; 95% confidence interval [CI], 1.119-16.857; p < 0.05). ConclusionThe occurrence of unexplained recurrent miscarriages is associated with the differential expression of key miRNAs in the sperms of patients spouses.