Follicular fluid and mural granulosa cells microRNA profiles vary in in vitro fertilization patients depending on their age and oocyte maturation stage

OBJECTIVE: To determine whether there is any difference in the follicular fluid (FF) microRNA (miRNA) profiles from in vitro fertilization (IVF) patients according to their age and oocyte maturation stage. DESIGN: Observational prospective study. SETTING: IVF clinic/hospital facilities. PATIENTS(S): We included 30 women with primary infertility undergoing intracytoplasmic sperm injection treatment and excluded patients with polycystic ovarian syndrome, endometriosis, severe male factor, and low ovarian reserve. INTERVENTION(S): After the collection of FF and granulosa cells from each patient, the samples were processed for total RNA extraction. RNA was pooled into different groups (three samples per pool) for microarray analysis to evaluate the expression of a total of 866 human miRNAs. Individual samples were analyzed to validate the pooled microarray results using real-time polymerase chain reaction. MAIN OUTCOME MEASURE(S): Evaluation of the expression of a total of 866 human miRNAs in FF and granulosa cells. RESULT(S): We identified only one differentially expressed miRNA, hsa-miR-424, which is present in higher proportions in FF from patients with advanced age. When we compared the FF from metaphase II (MII) versus GV (germinal vesicle) oocytes, we found 13 differentially expressed miRNAs (two up- and 11 downregulated). When we compared FF from MII versus MI, we found seven differentially expressed miRNAs in MII (three up- and four downregulated). CONCLUSION(S): We have described the FF miRNA profiles according to IVF patients' age and the maturation stage of their oocytes. This descriptive study may aid our understanding of the physiology and regulation of oocyte maturation and could identify some potential miRNA biomarkers for this process. CLINICAL TRIAL REGISTRATION NUMBER: Not applicable.