Effects of OPN and LIF expression in decidual and villous tissues on unexplained recurrent spontaneous abortion in the first trimester of pregnancy

Abstract

Abstract Objective Recurrent spontaneous abortion (RSA) is defined as a condition in which women suffer from two or more continuous spontaneous miscarriages. However, the etiology of a large proportion of women with RSA remains unknown. The study was conducted to investigate the effects of expression of osteopontin (OPN) and leukemic inhibitory factor (LIF) expression in decidual and villous tissues on unexplained RSA in the first trimester of pregnancy. Methods Twenty women with unexplained RSA in the first trimester of pregnancy were selected as study group, as well as 20 women with normal induced abortion in the first trimester of pregnancy were selected as control group. The decidual and villous tissues of participants in the two groups were collected. The expressions of OPN and LIF were detected by immunohistochemistry (IHC), immunofluorescence, western blotting and real-time polymerase chain reaction. The correlation between the expressions of OPN and LIF was analyzed. Results The OPN and LIF were mainly expressed in uterine epithelial cells and decidual cells, as well as pregnancy trophoblastic cells in villous tissues. The positive rates of OPN and LIF expression in decidual and villous tissues of the study group were significantly decreased, and the IHC scores were significantly lower compared with control group (P < 0.05). In the decidual tissues, the OPN and LIF were mainly co-located in uterine epithelial cells and decidual cells. While in the villous tissues, OPN and LIF were mainly co-located in gestational trophoblastocytes. The fluorescence intensities of OPN and LIF in decidual and villous tissues of the study group were significantly lower than that of the control group (P < 0.05). In addition, the protein and mRNA expression levels of OPN and LIF in decidual and villous tissues in study group were also significantly decreased compared with control group (P < 0.05). The protein and mRNA expression levels of OPN and LIF in decidual and villous tissues of the two groups were significantly positively correlated (P < 0.01). Conclusion The expressions of OPN and LIF in decidual and villous tissues of patients with unexplained RSA in the first trimester of pregnancy were significantly decreased, which may lead to reduced endometrial receptivity, and then cause RSA.