Abstract:  Objective：To analyze the expressions of miRNA-9, miRNA-18b, miRNA-19, miRNA-24, miRNA-199 and miRNA-320 in the follicular fluid and exosome of patients with polycystic ovary syndrome (PCOS), and to explore the potential roles of these miRNAs in the pathophysiological mechanism of PCOS. Methods: A total of 48 patients undergoing in vitro fertilization and embryo transfer (IVF-ET), including 23 PCOS patients and 25 controls, were enrolled. The follicular fluid was collected. The exosome from the follicular fluid was isolated using ultrafiltration. NTA, Western blotting and TEM were used to identify the exosmoe. The expressions of miRNA-9, miRNA-18b, miRNA-19, miRNA-24, miRNA-199 and miRNA-320 in the follicular fluid and exosome were examined by real-time quantitative PCR. Results: The expression level of miRNA-199 in the follicular fluid of PCOS patients was significantly higher than that in the control group (5.42±0.80 vs. 1.02±0.94, P＜0.01), while the expression level of miRNA-320 was significantly lower (0.47±0.06 vs. 1.23±0.09, P＜0.01). The expressions of miRNA-9, miRNA-18b, miRNA-19 and miRNA-24 were showed no significant differences between the two groups (P＞0.05). In exosomes, the expressions of miRNA-9 and miRNA-18b in the PCOS group were significantly higher than those in the control group (8.94±0.54 vs. 1.01±0.97，2.66±0.19 vs. 1.12±0.06, both P＜0.01), while the expressions of miRNA-199 and miRNA-320 were significantly lower (0.43±0.11 vs. 1.22±0.07, 0.53±0.09 vs. 1.18±0.15, both P＜0.01). Conclusions: It is helpful to analyze the expressions of miRNA-9, miRNA-18b and miRNA-199 in the follicular fliud and exosome of PCOS patients for us to explore the roles of miRNAs in the pathophysiological mechanism of PCOS.

Key words: Polycystic ovary syndrome, Follicular fluid, MicroRNAs, Exosomes