Relationship between embryo development and apoptotic gene expression of cumulus cells in poor responders and polycystic ovary syndrome

Abstract

Research questionIs there a relationship between embryo quality, pregnancy rates and apoptotic gene expression in cumulus cells of oocytes collected from patients with poor ovarian response and polycystic ovary syndrome? DesignFifty infertile couples who underwent assisted reproductive technology treatment were included in the study (Approval date 4 February 2020, number 03). The patients were divided into four group: control (n = 9; 90 oocytes), unexplained infertility (n = 8; 86 oocytes), polycystic ovary syndrome (PCOS) (n = 6; 137 oocytes) and poor ovarian response (POR) (n = 27; 124 oocytes). Cumulus cells were isolated individually from 437 oocytes obtained. Intracytoplasmic sperm injection was undertaken on 365 mature oocytes. The embryos were monitored. Caspase-3, Bax and Bcl-2 gene expressions of the cumulus cells were measured by real-time polymerase chain reaction. ResultsA significant and negative correlation was found between Bax and Bcl-2 expressions of the cumulus cells of poor-quality embryos. The increase in Caspase-3 gene expression in the POR group statistically decreases the pregnancy rates. Fertilization and good-quality embryo development of 365 oocytes whose cumulus cells were examined, however, were not associated with apoptotic gene expression. The Bax/Bcl-2 ratio was found to be significantly lower in cumulus cells of mature oocytes. ConclusionsOur results demonstrated no significant associations between fertilization, quality embryo development and apoptotic gene expression. Bax expression and the Bax/Bcl-2 ratio are high in immature oocyte cumulus cells has shown us that the apoptotic process may begin when the cumulus–oocyte connection exists.