Differential Expression of miR-93 and miR-21 in Granulosa Cells and Follicular Fluid of Polycystic Ovary Syndrome Associating with Different Phenotypes

Mohammad Naji,Saeid Nekoonam,Fardin Amidi,Ehsan Arefian,Reza Mahdian,Ashraf Aleyasin

doi:10.1038/s41598-017-13250-1

Abstract

The heterogeneous and multifactorial essence of polycystic ovary syndrome (PCOS) renders a remarkable significance to microRNAs (miRNAs). Normo-androgenic (NA) and hyperandrogenic (HA) PCOS patients were compared with matched healthy women. Expression of miRNAs and TGFβ signaling genes was studied by qRT-PCR and western blotting. Effect of androgen on expression of miR-93 and miR-21 and involvement of androgen receptor were appraised. In granulosa cells (GCs), miR-93 and miR-21 showed significantly increased levels in HA patients compared to NA patients. On the contrary, follicular fluid (FF) levels of both miRNAs were significantly decreased in HA group compared to control women. No significant change in the expression of miRNAs in serum samples was detected. Furthermore, mRNA levels of SMAD7 and TGFBR2 were significantly downregulated in GCs of HA group compared to NA and control subjects. TGFBR2 protein level was significantly decreased in HA patients compared to controls. Free testosterone and free androgen index were positively correlated with expression of miR-93 and miR-21 in GCs of PCOS group. Our findings show distinct molecular signature of different subtypes of PCOS. Intermediary position of miRNAs as androgen responsive factors may play critical role in the pathogenesis of PCOS in hyperandrogenic condition.

Highlights

Polycystic ovary syndrome (PCOS) is a common and complex multifactorial endocrinopathy affecting 8–12% of reproductive-aged women[1]
Ferriman-Gallwey score and Free androgen index (FAI) were elevated in polycystic ovary syndrome (PCOS) patients versus control subjects, and in HA PCOS patients compared to NA PCOS patients
Scrutinizing the role and differential expression of miRNAs in various tissues of PCOS patients has been the subject of increasing number of studies[33] which generally focused on miRNAs as potential biomarkers of the syndrome

Summary

Introduction

Polycystic ovary syndrome (PCOS) is a common and complex multifactorial endocrinopathy affecting 8–12% of reproductive-aged women[1]. To provide new insights into the pathogenesis and etiology of PCOS, miRNAs have received more attention from recent studies In this regard, the expression profiles of miRNAs in circulation and follicular fluid (FF) of PCOS patients have been investigated to find novel biomarkers and target genes that may contribute in the diseased phenotype[24,25]. In consideration of GCs dysfunction in PCOS and the importance of TGFβ signaling in folliculogenesis; we hypothesized that androgen excess milieu in PCOS may deregulate miRNAs with multiple targets in TGFβ signaling pathway. Relative expression of putative targets of miR-93 and miR-21 from TGFβ signaling pathway were investigated in GCs. We studied the involvement of androgen receptor (AR) in mediation of androgen effects on miRNAs and downstream targets

Methods

Results

Conclusion