Expression of microRNA in follicular fluid in women with and without PCOS

Abstract

Several studies have shown the expression of small non-coding microRNA (miRNA) changes in PCOS and their expression in follicular fluid has been described, though the number of studies remains small. In this prospective cohort study, miRNA were measured using quantitative polymerase chain reaction (qPCR) in 29 weight and aged matched anovulatory women with PCOS and 30 women without from follicular fluid taken at the time of oocyte retrieval who were undergoing in vitro fertilization (IVF); miRNA levels were determined from a miRNA data set. 176 miRNA were detected, of which 29 differed significantly between normal women and PCOS women. Of these, the top 7 (p < 0.015) were miR-381-3p, miR-199b-5p, miR-93-3p, miR-361-3p, miR-127-3p, miR-382-5p, miR-425-3p. In PCOS, miR-382-5p correlated with age and free androgen index (FAI), miR-199b-5p correlated with anti-mullerian hormone (AMH) and miR-93-3p correlated with C-reactive protein (CRP). In normal controls, miR-127-3p, miR-382-5p and miR-425-3p correlated with the fertilisation rate; miR-127-3p correlated with insulin resistance and miR-381-3p correlated with FAI. Ingenuity pathway assessment revealed that 12 of the significantly altered miRNA related to reproductive pathways, 12 miRNA related to the inflammatory disease pathway and 6 were implicated in benign pelvic disease. MiRNAs differed in the follicular fluid between PCOS and normal control women, correlating with age, FAI, inflammation and AMH in PCOS, and with BMI, fertilization rate (3 miRNA), insulin resistance, FAI and inflammation in control women, according to Ingenuity Pathway Analysis.

Figure 1

Volcano plot of microRNA detected in the follicular fluid between those women with PCOS (n = 29) versus normal women without PCOS (n = 30). Altered expression of microRNAs in a comparison between PCOS and controls are shown as fold change on the x-axis and the significance (p-value) of that fold change on the y-axis. Both are shown in log scale. Red dots: miRs with >2-fold change (+ or −) but not changing significantly. Yellow dots: miRs with >2-fold change and also changing significantly (p < 0.05).

Figure 2

Ingenuity pathway analysis of the significantly altered miRNA found in the follicular fluid showing that 12 of these miRNA were related to the genes involved in the Organismal Injury and Abnormalities, Reproductive System Disease pathway. Strongly upregulated and downregulated miRNA are represented with dark red and green color and vice versa.

Figure 3

Ingenuity pathway analysis of the significantly altered miRNA found in the follicular fluid showing that 12 of these miRNA were related to the genes involved in the Inflammatory disease pathway. Strongly upregulated and downregulated miRNA are represented with dark red and green color and vice versa.