Target gene repression mediated by miR-144 and miR-224 in cumulus cells is related to the success of oocyte in vitro maturation and fertilisation in patients with polycystic ovary syndrome (PCOS).

CONTEXT: In vitro maturation (IVM) of oocytes is an alternative approach for patients with polycystic ovary syndrome (PCOS) predisposing to ovarian hyperstimulation syndrome (OHSS). Transcriptomic analysis of cumulus cells (CC) may help make IVM more efficient. The aim of this study was to examine the impact of miR-144 and miR-224 and their candidate target genes (COX-2 and PTX-3 , respectively) expression on oocyte development in PCOS patients. METHODS: Immature oocytes were retrieved from 20 PCOS patients. After IVM, samples were divided into two groups: matured (M) and immatured (I) oocytes. ICSI was performed and the embryo quality was evaluated. qPCR was used to analyse miR-144, miR-224, COX-2 and PTX-3 expression levels in CCs of each group. KEY RESULTS: We found that the expression levels of miR-144 and miR-224 were lower and the COX-2 and PTX-3 mRNA levels were higher in CCs of M group than in CCs of I group. The expression level of miR-144 and miR-224 in unfertilised oocytes were higher than fertilised oocytes. The contrary results were observed for COX-2 and PTX-3 . A reduction pattern in the expression level of miR-144 and miR-224 and increasing pattern in the level of COX-2 and PTX-3 expression were observed in high quality compared to low quality embryos. CONCLUSIONS: The selected miRNAs were related to oocyte maturation, fertilisation and embryo development. These results support their critical involvement in oocyte development. IMPLICATIONS: Our findings may help reveal the mechanisms of post-transcriptional regulation by miR-144 and miR-224 during IVM procedure.

Expression of miR-21 &IL-4 in endometriosis.

BACKGROUND: Endometriosis characterized with existence of endometrial-like tissue outside the uterus. Fibrosis of ectopic lesions is an important feature of endometriosis. IL-4 induces fibrosis via fibroblast proliferation, collagen production and myofibroblast differentiation. Increasing of miR-21 expression promotes fibroblast activation and fibrosis expansion. The aim of study was to evaluate the expression of miR-21 and its relationship with IL-4 gene expression in endometrial ectopic and eutopic tissues of endometriosis patients. METHODS AND RESULTS: Ectopic and eutopic tissue samples were taken from 20 women with endometriosis, and control samples were taken from the endometrium of 20 endometriosis-free women. The relative expression of IL-4 and miR-21 evaluated by Real Time PCR. IL-4 relative gene expression was significantly increased in ectopic tissue compared to eutopic (p = 0.025) and control tissue (p = 0.021). The relative expression of miR-21 gene in ectopic tissue was increased compared to eutopic (p = 0.850) and control tissue (p = 0.978) but these differences were not significant. Also, the correlation between IL-4 and miR-21 relative gene expression was not significant (p = 0.083). CONCLUSION: The increased expression of miR-21 in endometrium of women with endometriosis may upregulate the IL-4 gene expression and lead to fibrosis. Further studies may suggest miR-21 and IL-4 as candidates for diagnosis of endometriosis.

The possible regulatory role of miR-514 and miR-642b in cumulus cells on the oocyte maturation in patients with polycystic ovary syndrome.

Polycystic ovary syndrome is a common endocrine disorder in reproductive-age women. Accordingly, abnormal microenvironment may negatively influence oocyte developmental competence as a result of the altered expression profile of cumulus cells (CCs), mainly the key players of oocyte maturation, such as epidermal growth factor receptor (EGFR) and prostaglandin E receptor-2 (PTGER2). This study aimed to examine the expression levels of miR-514, miR-642b, and their candidate target genes (EGFR and PTGER2, respectively) in CCs of immature and mature oocytes in patients with PCOS. A total of 40 oocytes at germinal vesicle (GV) and 40 oocytes at metaphase II (MII) stages were retrieved from 30 PCOS women. Quantitative real-time PCR was performed to analyze the expression level of miR-514, miR-642b, EGFR, and PTGER2 in cumulus cells (CCS) of each oocyte. The expression level of miRNAs and their candidate target genes were compared between CCs of GV and MII oocytes. Our study suggests an inverse relationship exists between the expression levels of miR-514 and EGFR, and miR-642b and PTGER2. Furthermore, we observed that CCs of GV oocytes had higher levels of EGFR and PTGER2 mRNA and lower levels of miR-514 and miR-642b expression compared to those of MII oocytes. The present study demonstrated that miR-514 and miR-642b can regulate oocyte development by targeting EGFR and PTGER2, respectively. Therefore, examination of these miRNAs in CCs could be promising parameters to predict oocyte competence in PCOS patients.