Purpose: To determine if microRNAs are differentially expressed in the follicular fluid of women with PCOS compared to fertile oocyte donors and identify associated altered gene expression.
Methods: Women undergoing IVF who met Rotterdam criteria for PCOS or who were fertile oocyte donors were recruited from a private IVF center. Individual follicle fluid was collected at the time of oocyte retrieval. MicroRNA analysis was performed using microarray and validated using real-time PCR on additional samples. Potential gene targets were identified and their expression analyzed by real time PCR.
Results: Microarray profiling of human follicular fluid revealed expression of 235 miRNAs, 29 were differentially expressed between the groups. Using PCR validation, 5 miRNAs (32, 34c, 135a, 18b, and 9) showed significantly increased expression in the PCOS group. Pathway analysis revealed genes involved in insulin regulation and inflammation. Three potential target genes were found to have significantly decreased expression in the PCOS group (interleukin 8, synaptogamin 1, and insulin receptor substrate 2).
Conclusions: MicroRNAs are differentially expressed in the follicular fluid of women with PCOS when compared to fertile oocyte donors. There is also altered expression of potential target genes associated with the PCOS phenotype.