The role of β-HCG and VEGF-MEK/ERK signaling pathway in villi angiogenesis in patients with missed abortion

To analyze the effects of the Human Chorionic Gonadotropin beta (β-hCG) and the VEGF-MEK/ERK signaling pathway on villi angiogenesis in early missed abortion.A total of 12 cases of women with missed abortion and 12 cases of women who had induced abortion voluntarily without any disease were included in the present study. The age, pregnancy time and gestation period in the control group corresponded to the missed abortion group. Wes Simple Western system and qRT-PCR were used to detect the expression of VEGF-MEK/ERK signaling pathway related proteins and genes in villous. Radioimmunoassay and Enzyme-linked immunosorbent assay were used to detect β-hCG and VEGF levels in serum. The microvascular density (MVD) in villous tissue was analyzed by immunohistochemical staining.The levels of β-hCG and VEGF in serum, the expression of VEGF-MEK/ERK signaling pathway and MVD in villous tissue of the missed abortion group were lower than those of the control group. In addition, compared with the control group, the layers of trophoblasts of the villous tissue in the missed abortion group became thinner significantly, the number of cells reduced, the cell structures were disorganized, and parts of the trophoblast cells were absent. Correlational analysis showed that the protein expression of ERK1/2 was positively correlated with MVD in missed abortion group.Our results reveal that decreased production of β-hCG in early pregnant women could down-regulate the expression of VEGF-MEK/ERK signal pathway, then reduce angiogenesis and eventually leading to the abnormal angiogenesis of villous, which may be an important mechanism of missed abortion.