| ObjectivePreeclampsia is the unique disease in gestation; it does great harm to the health of the mother and the baby. Its clinical features are mainly hypertension, edema, protein urine; and convulsion of arterioles all over the body is its fundamental pathological features. To know the pathogen and functional mechanism of this disease is the very important task in the field of modern perinatology. Etiology theory about Preeclampsia are immune mechanism, superficial nidaton of placenta, functional disorder of vascular endothelial cells, genetic factors and so on. At present it is commonly considered that superficial nidaton of placenta and reconstruction impediment of vessels are pathologic basis for the occurrence of preeclampsiaLox-1 (Lectin-like OX-LDL receptor 1) is one of SR (Scavenger Receptor) family, Lox-1 is mainly expressed in vascular endothelial cells and tissue rich in vessels such as lung and placenta. Lox-1 expression is up regulated by OxLDL tumor necrosis factor-α, hypertensin-Ⅱ, ET-1, IL-6, oxidant stressor and other factors. Under pathological conditions, OX-LDL is mediated by Lox-1 to injure vascular endothelium and make its function in disorder, help to form foam cells, promote proliferation of vascular smooth muscle cells and induce its apoptosis. Research abroad has detected Lox-1 expression in preeclampsia and normal placenta and apoptosis of sertoli cells, and has found that Lox-1 expression and sertoli cells' apoptosis in preeclampsia placental syncytiotrophoblast is significantly higher than that in normal placenta tissue. There is no research about this in China. Whether Lox-1 expression between low-grade preeclampsia and high-grade preeclampsia is significantly different or not, there is no report both home and abroad. Immunohistochemistry, western blot and semi-quantitative RT-PCR method is adopted to detect and compare Lox-1 expression both in normal placenta and preeclampsia (low-grade, high-grade), and to probe and discuss its possible function in the occurrence of preeclampsia and its relationship with disease degree of preeclampsia.Methods一,Objects of study40 cases of placenta of patients suffering from preeclamsia are collected from the Second Clinical Hospital of Chinese Medical University from January, 2006 to June, 2006, and in it there are 20 cases of low-grade preeclaimpsia, and 20 cases of high-grade preeclaimpsia.. The diagnosis criteria of preecliamsia are as follows: single pregnancy, no pregnancy and its complications. Diagnosis and category criteria are according to Gynemetrics (the 6th edition); 20 cases of normal pregnancy placenta of the same stage, 60 cases of pregnant women all gave birth by Cesarean section.二,Specimen Collection60 cases of placenta tissue specimen are immediately collected during the surgery. Some of the specimen is fixed by paraformal-dehydepa, dehydrated, embedded according the routine rules to provide for immunohistochemistry detection. Other fresh specimen is frozen in liquid nitrogen and then stored in-80℃deep-frozen refrigerator.三,Experiment Method(一) Immunohistochemistry is adopted to detect the expression of Lox-1 Normal pregnancy and preeclaimpsiaParaffin-embedded slices are routinely dewaxed and hydrated. The tissue slices are incubated in 3% H2O2 for 10 minutes at room temperature and then dealed with microwave. After that, experiment is carried on according to the instructions of SABC reagent. (二) RT-PCR is adopted to detect the expression of LOX-1 mRNA:Total RNA is collected from the tissue, viscosity and purity is calculated. CDNA is synthesized by mRNA reverse transcription, and then PCR reaction is carried out according to the instructions of reagent kit. The products of PCR is done with electrophoresis, imaged and analyzed.β-actin is used as inner control to be enlarged.(三) Western blot is used to detect the expression of Lox-1 protein:Placenta tissue is cracked by protein schizolysis liquid, and the protein is quantified. After the denaturation, electrophoresis, wiped film and sealing of the protein specimen extracted, the first antibody is added to incubated at 4°C over night, washed by TTBS, and then the second antibody(alkaline phosphates rabbit anti goat IgG)is added, and the complex is hybridized at room temperature on the shaking bed for 2 hours. Alkaline phosphates show the color. Gelatin image is analyzed and then gray value is measured.四,Statistic MethodTo compare the comparative gray value difference of the three groups of RT-PCR and western blot gray value difference, paired samples of t test is adopted, double P＜0.05 is considered as to have statistic difference in every statistic contrast.Results一,The results of immunohistochemistry staining of Lox-1:the tissue slices with the positive expression of Lox-1 show brow-yellow grain under the microscope, staining in syncytiotrophoblast, cytotrophoblast and vascular endothelial cells. All the slices show the color by immunohistochemistry, but high-grade preeclaimpsia show more Lox-1 positive cells, and has strong color; low-grade preeclaimpsia next to it; normal placenta tissue is the weakest.二,The results of Western blot and semi-quantitative RT-PCR of Lox-1: from normal placenta tissue, low-grade preeclaimpsia to high-grade preeclaimpsia, Lox-1mRNA and its protein expression increases. The three groups have significantly difference when every two of them is compared (p＜0.05)ConclusionThere is Lox-1 expression in normal placenta tissue, low-grade preeclaimpsia and high-grade preeclaimpsia, and also has an increasing trend, the three groups have significantly difference. And it predicts that Lox-1 may help with vascular endothelial cells' injury, the pathogenesis of placenta's ischemia and anoxia, and correlate with the disease status. Lox-1 may become one of the indexes to measure the progression preeclampsia.
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