ABSTRACT
Placentation,which is critical for maternal-fetal exchange of nutrients and gases,is a complicated process comprising stepwise vasculogenesis and angiogenesis.Hypoxia caused by impairedtrophoblast invasion may cause various angiogenic abnormalities in human placenta.The Notchl signaling pathway plays an important role in the regulation of angiogenesis.The angiogenesis of human umbilical vein endothelial cells (HUVECs) under normal/hypoxic conditions and the mRNA/protein level of Notchl/Dell4/Jaggedl were investigated in this study.The effects of DAPT/JAG-1 on the migration of HUVECs were also assessed by cell wound healing assay,so as to discover the possible role of notchl signaling pathway in the angiogenesis of human placenta.The results showed that angiogenic ability of HUVECs was seriously reduced under hypoxic conditions.The mRNA and protein levels of Notchl/Dell4/Jaggedl were decreased in the hypoxic group compared to the control one.In addition,the migration capability of HUVECs was significantly obstructed when treated with DAPT and under hopoxic condition,but promoted when treated with JAG-1.The above results demonstrate that hypoxia downregulates the angiogenesis in human placenta via Notch 1 signaling pathway.
ABSTRACT
The mechanism of injury on the human glomerular endothelial cells (ciGENC) induced by preeclampsia serum was investigated.Concentration of maternal serum sFlt-1 protein was detected by ELISA.Fluorescently-labeled bovine serum albumin infiltrating through lower chamber of Transwell was measured by multifunction microplate reader.Morphologic change of ciGENC was observed under inverted phase contrast microscope.The concentration of sflt-1 in preeclampsia groups was significantly increased as compared with control group (P＜0.01).Permeability in preeclampsia groups was significantly increased as compared with control group (P＜0.01).By contrast with severe preeclampsia group,the permeability of ciGENC monolayer in mild preeclampsia group was decreased significantly (P＜0.05).Intervention of exogenous VEGF significantly decreased permeability of ciGENC in preeclampsia groups.It was concluded that sFlt-1 increased ciGENC permeability by damaging integrity of endothelial barrier function.
ABSTRACT
This study examined the effect of over-expression of sFlt-1 by trophoblasts on the barrier function of glomerular endothelial cells and the role of VEGF in this process in order to explore the pathogenesis of glomerular disease in preeclampsia.SFlt-1 expression in the human trophoblasts (TEV-1 cells) was enhanced by transfecting sFlt-1 plasmid DNA into TEV-1 cells.The monolayer barrier function of glomerular endothelial cells (ciGEnCs) was determined by measuring the fluorescence intensity of bovine serum albumin (BSA) that crossed the monolayer of glomerular endothelial cells.The results showed that the over-expression of sFlt-1 by TEV-1 cells led to the barrier dysfunction of ciGEnCs,and the exogenous VEGF could alleviate the ciGEnCs dysfunction resulting from the over-expression of sFlt-1 to a certain extent.It was concluded that the dysregulation of sFlt-1 and VEGF in preeclamptic pregnancy may contribute to the barrier dysfunction of glomerular endothelial cells,and VEGF may play an important role in maintaining the barrier function of glomerular endothelial cells,but it may not be the sole factor.
ABSTRACT
This study examined the association of expression of vascular endothelial growth factor(VEGF),a promoter of angiogenesis,with endothelium dysfunction in preeclampsia.The level of VEGF protein and mRNA in the placenta and peripheral blood samples of 30 preeclampsia patients and 30 normotensive pregnant women was measured by immunohistochemistry,real-time reverse transcriptase-polymerase chain reaction(RT-PCR)and enzyme-linked immunosorbent assay(ELISA),respectively.VEGF expression in the human umbilical vein endothelial cells(HUVECs)was blocked by small interfering RNAs(siRNAs).The monolayer barrier function of HUVECs was determined by measuring the fluorescence intensity of BSA that crossed the HUVEC monolayers.The cell proliferation and cell-secreted nitric oxide(NO)level were detected by MTT method and nitrate reductase assay,respectively.The results showed that VEGF was expressed in the syncytiotrophoblasts and endothelial cells of vessels and capillaries in the placenta tissue.The serum level of VEGF in the preeclampsia patients was significantly decreased as compared with that in normal pregnant subjects,although VEGF mRNA expression in the placenta tissue of preeclampsia patients remained still high.Moreover,VEGF deficit could lead to endothelium cell dysfunction,and the administration of VEGF could protect endothelium cells from injury.It was concluded that lack of VEGF contributes to endothelium dysfunction,which may lead to the occurrence and development of preeclampsia.
ABSTRACT
The effects of leptin on cytotrophoblast proliferation and invasion activity were investigated.Immunohistochemistry was used to determine the placental expression of leptin in first-trimester preg-nancy. By using RT-PCR and quantitative real-time PCR, the expression of leptin in cytotrophoblast and the effect of leptin on cytotrophoblast secretion were detected. The potential of cell proliferation, inva-siveness and migration was assessed by MTT, Transwell invasion assay and migration assay respec-tively when the cytotrophoblast was cultured with different concentrations of leptin. The results showed that: (1) Leptin was distributed diffusely around cell membrane, in cytoplasma, and on nuclear mem-brane of cytotrophoblast; (2) Leptin mRNA was expressed in cytotrophoblast. Ten ng/mL leptin could promote the secretion of cytotrophoblast significantly (P<0.01); (3) After culture with different concen-trations of leptin for 24 h or longer, the proliferation of cytotrophoblast was inhibited, while in 24 h leptin could promote cytotrophoblast invasion and migration. Leptin at a concentration of 500 ng/mL could promote cytotrophoblast invasiveness and migration significantly as compared with controls (P<0.05). It was suggested that leptin could inhibit cytotrophoblast proliferation, and promote cytotro-phoblast invasion and migration activity.
ABSTRACT
To investigate the expression of osteopontin (OPN) and its receptor integrin αvβ3 in the placental tissue from pregnant women complicated with preeelampsia,the expression of OPN and αvβ3 in the placenta of the pregnant women with preeclampsia and healthy pregnant women was detected by immunohistochemistry,Western blotting and RT-PCR. Our results showed that OPN and αvβ3 protein were expressed in the placenta from normal pregnant woman and those with preeclampsia. OPN was located in the placental syncytiotrophoblasts and the cytoplasm of capillary endothelial cells and integrin αvβ3 was mainly expressed on the surface of trophoblast cells. Expression of OPN and integrin αvβ3 in the placental tissue from preeclampsia subjects was significantly lower than that from the control group (P＜0.05). Compared with the control group,expression of OPN in the placental tissue from preeclampsia group was significantly lower (P＜0.05) but there was no significant difference in the expression of αv and β3 between the preeclampsia group and the controls. It is concluded that OPN and its receptor integrin αvβ3 may be involved in the pathogenesis of preeclampsia.