AUTHOR=Li Anji , Ni Zhexin , Zhang Jie , Cai Zailong , Kuang Yanping , Yu Chaoqin 

TITLE=Transferrin Insufficiency and Iron Overload in Follicular Fluid Contribute to Oocyte Dysmaturity in Infertile Women With Advanced Endometriosis

JOURNAL=Frontiers in Endocrinology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2020.00391

DOI=10.3389/fendo.2020.00391

ISSN=1664-2392

ABSTRACT=<p><bold>Purpose:</bold> To screen out specific protein with different concentration in follicular fluid from advanced endometriosis and determine its direct effect on mouse oocytes matured <italic>in vitro</italic>.</p><p><bold>Methods:</bold> FF samples were obtained from 25 patients (EMS group, <italic>n</italic> = 15; control group, <italic>n</italic> = 10) to screen the differential proteins by using iTRAQ Labeling and 2D LC-MS. Transferrin (TRF) in was found significantly decreased in EMS group, which was verified using ELISA in enlarged FF samples (EMS group, <italic>n</italic> = 31; control group, <italic>n</italic> = 27). The contents of ferric ion in FFs were detected by ELISA and TRF saturations were calculated in two groups. Germinal vesicle (GV) oocytes of mouse were maturated <italic>in vitro</italic> interfered with the FFs in five groups, whose concentrations of TRF were modulated, and maturation <italic>in vitro</italic> rates were compared among groups.</p><p><bold>Results:</bold> The reduced concentration of TRF with three analogs and increased concentration of ferric ion were found in the FF of the EMS group (<italic>p</italic> &lt; 0.05). The numerical values of TSAT was 54.8% in EMS group, indicating iron overload in the FF. The EMS-FF showed significantly decreased maturation <italic>in vitro</italic> rate (<italic>p</italic> &lt; 0.05) of mouse oocytes, which was improved with the supplementation of TRF, compared with the control-FF. The effect was blocked by the TRF antibody (<italic>p</italic> &lt; 0.05).</p><p><bold>Conclusions:</bold> Being aware of the relatively small sample size, our results possibly suggest that TRF insufficiency and iron overload in FF from advanced EMS contribute to oocytes dysmaturity, which may be a cause of EMS-related infertility.</p>