P-86: Evaluation of Telomere Length, Telomerase and Telomeric Repeat Containing RNA (TERRA) Expression Levels in Cumulus Cells of PCOS Patients
Polycystic ovary syndrome (PCOS) is one of the reasons of infertility in women with chronic anovulation. Ovulation process is tightly regulated by molecular mechanisms controlling proliferation/differentiation of cells. Telomeres, TTAGGG tandem repeats, are transcribed into a non coding RNA, named TERRA. Recent studies suggest that TERRA sustain several important functions at chromosome end such as regulation of telomere length through modulation of telomerase. Telomerase is an enzyme that binds to the telomere and maintains telomere length and integrity. In the reproductive system, telomerase is present in germ cells, proliferative granulosa cells and germline stem cells but it is absent in differentiated cells. Each oocyte is covered by cumulus cells (CCs) which are in bi-directional communication. The role of these cells in the maturation, ovulation and fertilization of oocytes has been studied extensively. It seems that the length of telomere is related to proliferation and differentiation events during follicular development including the mechanisms which regulate successful reproduction.
Materials and methods
Cumulus cells and blood samples were collected from 20 PCOS patients and 20 healthy women with male factor infertility as control group. Informed consents were obtained from the participants. Expression of telomerase, TERRA genes were evaluated in CCs and telomere length in blood samples were quantified by using q-PCR.
Obtained data from CCs showed increase in mRNA levels of telomerase and also significant increase in TERRA transcription level in PCOS patients vs. control group. Hoewever, there were no significant alterations in telomere length of blood cells among studied groups.
According to increased telomerase expression and different roles of TERRA, we speculate that TERRA mRNA increasing may have a role in inhibiting telomerase activity of cumulus cells which at least affect on their telomere length. Overall, these findings suggest a correlation of telomerase and TERRA levels with infertility anovulation in PCOS patients.