The Quantitive Measurement Of Midkine And Its Expression In Preeclampsia

Midkine (MK) is a important member of heparin-binding growth factors. It is widely expressed in vertebrates and expressed in the second trimester of human fetal epithelial, mesenchymal tissue and nervous tissue involved in growth, survival, migration, and differentiation of various target cells. It plays a important role in the development of the epithelium and nerve tissue of the fetal. However, the expression of MK in adult tissue is very restricted and is difficult to be detected. In recent years many experiments show that MK have important biological activities including fibrinolysis, anti-apoptosis, mitogenic, cell transforming, angiogenesis and chemotaxis. To explore the relationship between MK and preeclampsia, we examined the MK in maternal blood, umbilical cord blood and placenta tissue of non-pregnant women, normal pregnant women and patients with preeclampsia. There is not any study that analyzed the expression of MK in preeclampsia before and the outcomes are expected to be helpful to the etiopathogenisis, diagnosis, prevention, gene therapy and therapeutic effect evaluation of preeclampsia.20 cases of mild preeclampsia and 20 cases of severe preeclampsia were enrolled in the study group. The control group include 10 cases of non-pregnant women and 20 cases of normal pregnant women during the same period. Both the maternal serum and umbilical cord serum MK were determined by ELISA and the MK in placentas of all the pregnant were detected by immunohistochemistry.The results of this study show: 1. There was no MK in the serum of the 10 non-pregnant women. 2. The maternal serum MK results: The MK level of the normal pregnant group was 20.2534±6.7117 pg/ml, the mild preeclampsia group was 43.9894±6.6682 pg/ml and the severe preeclampsia group was 3.3891±3.9299 pg/ml. The MK level of the mild preeclampsia group was higher than the normal pregnant group(P<0.05). The MK level of severe preeclampsia group was lower than the normal pregnant group(P<0.05). There was no significiant difference between severe preeclampsia group and non-pregnant women(P>0.05). 3. The umbilical cord serum MK results: The MK level of the normal pregnant group was 15.0941±16.9984 pg/ml, the mild preeclampsia group was 46.2476±14.2191 pg/ml and the severe preeclampsia group was 3.3975±4.8522 pg/ml. The umbilical cord serum MK level of mild preeclampsia group was higher than the normal pregnant group (P<0.05) and that of the severe preeclampsia group was lower than the normal pregnant group (P <0.05). 4. The placenta MK results: The mild preeclampsia placenta MK was significantly higher than that of the normal pregnancy group (P<0.05), and the severe preeclampsia placenta MK was lower than that of normal pregnancy group (P<0.05).All of these results above show that: there is significant relationship between MK and pregnancy. There is no MK in non-pregnant women. MK can be expressed both in serum and in placenta. The MK level of patients with mild preeclampsia is higher than that of normal pregnant women both in serum and in placenta, however, the MK of patients with severe preeclampsia is low expressed or even isn't expressed both in serum and in placenta. On the basis of the pathophysiological changes of preeclampsia, it can be deduced that the MK level will step up first during the early stage of preeclampsia, then it will decrease to a level lower than the normal pregnancy when the disease aggravate more. Thus, it will lead to the disorders of vascular proliferation and differentiation, which result in the insufficiency of blood supply of the systemic organs. The fetal development will be restricted because of the blood shortage of the uterus and placenta, especially the fetal lung. Finally fetal distress and neonatal asphyxia occur. The result we have acquired is expected to be helpful to the etiopathogenisis and gene therapy of preeclampsia. We can cure the preeclampsia and improve the prognosis of fetus and neonatus by increasing the MK level, which may promote angiogenesis, cell proliferation, differentiation, anti-apoptosis and make the fetal lung fully developed. In addition, the application of transgenic MK may develop the fetal teeth much more and reduce the future incidence of odontopathy at the same time. The result is expected to be applied to the clinic and confirmed by further long-term follow-up.