Expression Of Leukemia Inhibitory Factor In Human Chorionic Villi And Deciduas Of Normal Early Pregnancy\Threatened Abortion And Inevitable Abortion

Background: Leukemia inhibitory factor (LIF), identified first in 1986 is a pleiotropic cytokine of the interleukin-6 family, meaning that it has effects on many different cell types and that its activities are not restricted to cells of one lineage. LIF was primarily described as a product to activate the differentiation and to inhibit the proliferation of the Ml murine leukemic cell line. Since 1988,some foreign researchers have proved that LIF is able to support the growth and inhibit the differentiation of normal embryonic stem cells which can differentiate to be different cell types. More and more researches on the effects of LIF on human reproduction were studied. Based on the Extensive work, some scholars figured out that LIF play a very important role in the whole process of human reproduction. As we all know, the microenvironment of human follicles is critical to normal growth of oocytes and timely ovulation . LIF in follicular fluid can promote the growth of oocytes and improve the quality of the follicles. And in addition, when the follicles matured, the flare-up of LIF protein in follicular fluid may regulate the ovulation in some way andsome scholars presented that the level of LIF in follicular fluid can be described as a marker of oocyte quality and predicting ovulation and correlated with embryo quality. LIF also can regulate the implantation and growth of blastocyst in a time and dose dependence way. The implantation of blastocyst is a key step to mammals pregnancy and although the mechanism by which factors regulate the implantation of blastocyst is incompletely understood, studies have strongly suggested the interaction between the blastocyst and the deciduas is critical to a successful pregnancy. Many autocrine and paracrine factors including LIF take part in the regulation of the process. The successful progress of a pregnancy relies on complex interactions between these factors and other polypeptides or steroid hormones. On the basis of reports gathered from animal models, the hatching rate and the survive rate of blastocysts dealt with LIF can be improved .Both the trophoblast cells and inner cell mass also can proliferated acceleratively; But the embyos with deficiency of LIF gene usually are smaller than normal embyos at the same phase, and most of them would abort spontaneously. Many studies showed that LIF expressed not only in the blastocyst and deciduas in preimplantation phase but also in the original 6 months of pregnancy. All of these supported that LIF played an important role in the wholeprocession of pregnancy.In spite of the improvement of the life and medical condition, the incidence of spontaneous abortion has been estimated at about 10%-15% of all pregnancies, and the most of these are early abortion. It is known that, abortion hurts deeply not only the body but also the mentality of woman, and recurrent abortions may lead to reproductive sequelaes such as damage to the deciduas , menorrhagia , hypermenorrhea and infertility and so on. So the studies on early abortion are very important to both the prevention and treatment of spontaneous abortion and the understand of the basic theories on abortion. The familiar reason such as chromosomally abnormal fetuses and uterine developmental abnormalities and cervical incompetence and so on can only explain a portion of spontaneous abortion.The reasons for many abortions are unknown to both patients and doctors. Based on the extensive work in animal models evaluating the role of LIF in mammalian reproduction, some scholars put forward that the low expression of LIF may be an important reason for early abortion. It is anticipated that when the mechanisms underlying are elucidated, spontaneous abortion will be more precisely understood and hence able to be effectively controlled.Recently, scholars began to pay much attention to the effects of LIF on infertility and spontaneous abortion. Some researchers obtained uterine flushings samples from normal fertile women, women with unexplained infertility, and women having recurrent miscarriage...