Does LIN28B gene dysregulation make women more likely to abort?

BACKGROUND: LIN28B plays an important role in early embryonic development, but its role in villous trophoblast implantation and differentiation remains unknown. This study aims to verify the role of LIN28B in trophoblastic villous tissue and cells from women with URSA (unexplained recurrent spontaneous abortion) and artificial termination of pregnancy (negative control, NC). METHODS: The LIN28B gene and its protein expression level were detected with real-time quantitative PCR, Western immunoblotting analysis, and immunocytochemistry. The gene was also overexpressed in chorionic villous cell lines (HTR-8/SVneo and BeWo) to examine its effect on trophoblast function. RESULTS: The expression of LIN28B mRNA and protein of URSA villi was lower than that in the NC group. At the cellular level, overexpression of LIN28B enhanced cellular migration, and invasion, and inhibited apoptosis. LIN28B may inhibit apoptosis by promoting Akt phosphorylation and by inhibiting Bad phosphorylation and Bcl-2 expression. In addition, LIN28B inhibited cell fusion and reduced cellular syncytia. CONCLUSIONS: LIN28B can inhibit cell invasion and migration in vitro and promote apoptosis and fusion. The low expression of LIN28B in URSA villous trophoblast cells may be one of the causes of abortion. The role of LIN28B in villous trophoblasts needs further study. LAY SUMMARY: Propagation of offspring is of great significance to the continuation of the human race. However, continuous pregnancy is more difficult for some women, especially women who have multiple miscarriages. One important contributor is the cessation of development caused by genetic factors of the embryo, but there are still many unknown reasons. We investigated the LIN28B gene which is a possible pathogenic factor in the placenta. We collected 25 cases of abortion in the experimental group (unexplained recurrent abortion group) and 25 in the control group (artificial termination of pregnancy group): on average at 7-8 weeks of pregnancy. We tested the function of lin28b in these samples and verified its function in cell lines. LIN28B plays an important role in maintaining early pregnancy by promoting the invasion of villous cells, inhibiting apoptosis and fusion, and the reduction of LIN28B expression may lead to the occurrence of early miscarriage.

Relationship between a low ratio of serum estradiol to follicle number and fertility treatment outcomes: A retrospective cohort study of 516 cases.

The aim of this retrospective study was to examine how a low estradiol/follicle (E2/fol) may be related to in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI)-embryo transfer outcomes in polycystic ovary syndrome (PCOS) and non-PCOS patients, respectively. Between 2013 and 2017, 516 IVF/ICSI cycles (146 cycles in PCOS patients and 370 cycles in non-PCOS patients) with a long gonadotrophin releasing hormone receptor agonist protocol-including 338 involved fresh transfer cycles (89 cycles in PCOS patients and 249 cycles in non-PCOS patients)-were conducted. Outcomes were compared between 5 groups of PCOS patients defined by E2/fol (pg/mL) as follows: A, <140; B, 140 to 210; C, 210 to 280; D, 280 to 350; and E, >350. Non-PCOS patients' outcomes are grouped as well. Whether in PCOS or non-PCOS patients, those in the lowest E2/fol group (<140 pg/mL) tended to be younger, and with a greater body mass index (BMI) and antral follicle count (AFC), than the patients in the other groups. Relative to the other groups, Group A showed a lower number and rate of oocytes, higher single pronucleus (1PN) and triple pronucleus (3PN) formation rate, early and advanced abortion rates, but these did not differ significantly from those of the other groups, it perhaps due to the limited sample size. Group A have a higher incidence of moderate or severe ovarian hyperstimulation syndrome than the other groups in non-PCOS patients (P > .05). Whether in PCOS or non-PCOS patients, greater BMI, greater AFC, and younger age may favor the phenomenon of low E2/fol. In turn, low E2/fol may reduce the oocyte retrieval rate and increase the risk of 1PN and 3PN formation and abortion.