| Background and Objectives:Gestational hypertensive disorders refer to the concomitance of pregnancy and hypertension disease, with the rate of 5-20%. The disease can be harmful to the maternal and fetal health severely. Hypertensive disorders in pregnancy include five subgroups:chronic hypertension complicating pregnancy, gestational hypertension, preeclampsia, eclampsia and preeclampsia superimposed upon chronic hypertension. Preeclampsia often occurs after 20 weeks of gestation and is a multiple organ system disease peculiar to pregnancy. The main clinical symptoms were sudden hypertension, proteinuria, and edema. For severe cases, patients may appear symptom of dizziness, blurred vision, severe hypo-albuminemia, thrombocytopenia, etc. The related serious complications of preeclampsia include placental abruption, intrauterine growth restriction, low birth weight, preterm delivery et al. The further development of preeclampsia may be associated with preeclampsia onset of HELLP syndrome (hemolysis, elevated liver enzymes, and low platelets syndrome) when neurological dysfunction, impaired liver function and blood system diseases occurred, serious harm to the maternal and perinatal life safety. Some foreign literature reports that hypertension disorders of pregnancy account for 18% mortality of pregnant women worldwide. Additionally, more and more evidences indicate that the risks for cardiovascular, cerebrovascular and metabolic disease in patients with a history of gestational hypertension disease and their newborns increase in the future. Termination of pregnancy is the most effective treatment for severe preeclampsia. Yet, increased rates of abortion and preterm birth often accompany the termination, and finally the perinatal mortality and morbidity increase. We should stress early prevention and early treatment. However, the definite etiology of preeclampsia is elusive. Placental dysfunction (induced by angiogenic factors and mediators of inflammation) may involve in preeclampsia. And the imbalance of inflammation related factors has been found in patients with preeclampsia. Gas6 (growth arrest-specific protein 6), is a kind of secreted protein coded by growth arrest-specific gene. Gas6 can be detected in various tissues and cells, with over expression in kidney, placenta etc and almost no secretion in liver. Axl, as one of the TAM receptor tyrosine family members, has high compatibility for its ligand gas6. A wide variety of biological effects can be induced by the gas6-TAM pathway in different tissues and the pathway closely relates to the vascular homeostasis, inflammation reaction and immune regulation. So we hypothesize that gas6 might involve the incidence and progress of preeclampsia. So our aim is to examine the significance of gas6 in severe preeclampsia by investigating the location and expression level changes of gas6 in the placenta.Design and methods:Sixty-two cases delivered by cesarean in our hospital were included in the scope of this study, including 32 patients with severe preeclampsia (SP) as the experimental group and 30 cases of normal late pregnant women (NP) as the control group. The placental along with part of decidual specimens were collected. Enzyme linked immunohistochemical technique was adopted to identify gas6 protein localization in placenta and decidua, while real time quantitative PCR was administered for quantitative analysis of expression levels of gas6 mRNa and western Blot was carried out for quantitative analysis of expression levels of gas6 protein in placenta. Further, we analyzed the correlation between gas6 levels in the placenta with variety clinical indicators.Results:1. Compared to the NP group, the gestational age, serum albumin and platelet were much lower while the blood pressure, free fatty acids, serum creatinine were higher in the SP group.2. The location expressions of gas6 protein:gas6 proteins expressed mostly in the cytoplasm and nucleus of syncytiotrophoblast in placental tissue and decidual cells in decidual tissue and gas6 protein stained deeper in placenta of patients with severe preeclampsia.3. The quantitative expressions of gas6 mRNa:the expression levels of gas6 mRNa were elevated distinctly in SP group(0.596±0.380) compared to the NP group (0.337±0.223) (P＜0.05).4. The quantitative expressions of gas6 protein:gas6 protein expression levels were increased in SP group compared to the NP group with statistical difference (P<0.05) 5.Correlation between placental gas6 mRNa expression levels and various clinical parameters:correlation analysis revealed that gas6 mRNa levels were positively associated with body mass index, the blood pressure, free fatty acids while negatively correlated with albumin.Conclusions:1. Both the placental and decidual tissues showed staining for gas6 in women of SP and NP groups and gas6 protein stained deeper in placenta of patients with severe preeclampsia. These results suggested that gas6 can be secreted by the placenta and decidua cells, and may participate in the occurrence, development process of regulation of normal pregnancy and preeclampsia.2. The gas6 mRNa and protein expression increased markedly in placenta tissues of preeclampsia patients than in normal pregnant women, which suggested that gas6 possible involved in the origin and progress of preeclampsia through some mechanism.3. The gas6 mRNa expression levels were positively related to body mass index, the blood pressure, free fatty acids, yet negatively correlated to albumin. The findings suggested that gas6 might influence the body metabolism and further involved in the occurrence and development of preeclampsia... |
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