Evaluating the Differential Expression of miR-146a, miR-222, and miR-9 in Matched Serum and Follicular Fluid of Polycystic Ovary Syndrome Patients: Profiling and Predictive Value

Polycystic ovary syndrome (PCOS) is the most prevalent endocrine disorder of women in reproductive age with significant effects on reproductive and metabolic functions. Many molecular players may be involved in PCOS pathology; however, miRNAs possess great ability in gene expression control in normal ovarian function and folliculogenesis. We appraised the relative expression of miR-146a, miR-222, miR-9, and miR-224 in serum and follicular fluid (FF) of PCOS patients compared to control subjects. PCOS (n = 35) and control (n = 30) subjects were recruited in the study during their enrolment in IVF cycles. Serum and FF of human subjects were collected and stored. Total RNA was isolated from samples and cDNA was synthesized using miRNA-specific stem-loop RT primers. Quantitative real-time PCR was used to evaluate the expression of miRNAs relative to U6 expression. The predictive value of miRNAs' expression for discrimination of PCOS patients from control subjects was evaluated by receiver-operating characteristic (ROC) curve analysis. miR-224 was not detected in serum and FF samples. Significantly, higher levels of miR-146a and miR-9 in serum of PCOS group were detected. In contrast, relative expression of miR-146a and miR-9 significantly decreased in FF. In PCOS group, relative expression of all detected miRNAs was elevated in serum in comparison to FF, whereas in control group no change was noticed. Combination of FF miRNAs showed improved predictive value with area under the ROC curve (AUC) of 0.84, 93.8% sensitivity, and 83.3% specificity. Contradicting alternations of miRNAs in serum and FF are indicative of different sources of miRNAs in body fluids. Presumptive target genes of studied miRNAs in signalling pathways may show the potential role of these miRNA in folliculogenesis.