[Seminal plasma miR-26a-5p influences sperm DNA integrity by targeting and regulating the PTEN gene]

By analyzing the differential miRNA in seminal plasma between individuals with normal and abnormal sperm DNA fragmentation index（DFI）, we aim to identify miRNA that may impact sperm DNA integrity and target genes, and attempt to analyze their potential mechanisms of action.

A total of 161 study subjects were collected and divided into normal control group, DFI-medium group and DFI-abnormal group based on the DFI detection values. Differential miRNA were identified through miRNA chip analysis. Through bioinformatics analysis and target gene prediction, miRNA related to DFI and specific target genes were identified. The relative expression levels of differential miRNA and target genes in each group were compared to explore the impact of their differential expression on DFI.

Through miRNA chip analysis, a total of 11 differential miRNA were detected. Bioinformatics analysis suggested that miR-26a-5p may be associated with reduced sperm DNA integrity. And gene prediction indicated that PTEN was a specific target gene of miR-26a-5p. Compared to the normal control group, the relative expression levels of miR-26a-5p in both the DFI-medium group and the DFI-abnormal group showed a decrease, while the relative expression levels of PTEN showed an increase. The relative expression levels of miR-26a-5p in all groups were negatively correlated with DFI values, while the relative expression levels of PTEN showed a positive correlation with DFI values in the DFI-medium group and the DFI-abnormal group. The AUC of miR-26a-5p in the DFI-medium group was 0.740 (P<0.05), with a sensitivity of 73.6% and a specificity of 71.5%; the AUC of PTEN was 0.797 (P<0.05), with a sensitivity of 76.5% and a specificity of 78.4%. In the DFI-abnormal group, the AUC of miR-26a-5p was 0.848 (P<0.05), with a sensitivity of 81.3% and a specificity of 78.1%. While the AUC of PTEN was 0.763 (P<0.05), with a sensitivity of 77.2% and a specificity of 80.2%.

miR-26a-5p affects the integrity of sperm DNA by regulating the expression of PTEN negatively. The relative expression levels of seminal plasma miR-26a-5p and PTEN have good diagnostic value for sperm DNA integrity damage, which can help in the etiological diagnosis and prognosis analysis of abnormal DFI. This provides a diagnostic and treatment approach for the study and diagnosis of DFI abnormalities without clear etiology.