Comprehensive Profiling of microRNA Biomarkers for the Assessment of Male Infertility

Introduction Male infertility is a global health concern, and conventional semen analysis often provides limited insight into underlying molecular mechanisms. Seminal plasma microRNAs (miRNAs) have emerged as promising non-invasive biomarkers reflecting spermatogenic and epididymal function. This study investigated the expression of eight candidate miRNAs in men with asthenozoospermia, oligozoospermia, teratozoospermia, and fertile controls. Methods Semen samples (n=22 per group) were classified according to the WHO 2010 criteria. Total RNA was extracted from seminal plasma, and miRNA expression was quantified by real-time quantitative polymerase chain reaction (RT-qPCR) using miR-532-5p as the endogenous control. Relative expression was calculated using the ΔΔCt method. Statistical comparisons were performed using Student's t-test, and diagnostic potential was evaluated by receiver operating characteristic (ROC) analysis. Results In asthenozoospermia, miR-139-5p was significantly downregulated, showing the highest diagnostic potential (area under the curve (AUC)=0.88), while other miRNAs demonstrated minimal changes. In oligozoospermia, moderate expression alterations were observed for miR-932-5p and miR-942-5p, with fair diagnostic performance. Teratozoospermia exhibited no statistically significant miRNA differences, though some candidates showed weak-to-fair ROC-based diagnostic ability (AUC range: 0.69-0.88). Conclusion Seminal plasma miRNAs display phenotype-specific expression patterns and potential as non-invasive biomarkers for male infertility. miR-139-5p appears most promising for asthenozoospermia, while miR-932-5p and miR-942-5p may have relevance in oligozoospermia. These preliminary findings, derived from a modest sample size and exploratory design, warrant validation in independent, larger cohorts to confirm reproducibility and clinical utility.