Endothelial Cells In Preeclampsia Research Articles

Tumor necrosis factor alpha expression is increased in maternal microvascular endothelial cells in preeclampsia

ABSTRACT Objective: The aim of this study was to explore the expression and effects of tumor necrosis factor alpha (TNFα) in maternal endothelial cells in preeclampsia (PE). Methods: Expression levels in primary microvascular endothelial cells (MVEC) isolated from patients with severe preeclampsia (PE) and normal pregnancies were determined by RT-qPCR with or without treatment of TNFα and inhibitors for downstream signaling. Results: PE MVEC exhibited increased basal TNFα expression. TNFα treatment increased TNFα, VCAM, and endocan expression in MVEC. Conclusion: TNFα expression is increased in PE MVEC and the treatment of these cells with exogenous TNFα modifies their gene expression.

MiR-141-3p downregulation promotes tube formation, migration, invasion and inhibits apoptosis in hypoxia-induced human umbilical vein endothelial cells by targeting Notch2

Vascular endothelial cell damage is regarded as the carrier in the progression of the pathological changes of preeclampsia (PE) from the placenta to maternal organs. MicroRNA (miR)-141-3p was aberrantly expressed during PE pathogenesis. We investigated the role of miR-141-3p in regulating the biological behaviors of endothelial cells in PE. Human umbilical vein endothelial cells (HUVECs) were isolated from the human umbilical cords and cultured under hypoxia condition to establish PE models. The binding of miR-141-3p and Notch2 was confirmed by dual-luciferase reporter assay. HUVECs were transfected with miR-141-3p inhibitor and siRNA-Notch2. The viability, vascularization capability, migration, and invasion of HUVECs were evaluated by MTT, tube formation, and Transwell assays. Cell apoptosis was measured via flow cytometry. The expressions of miR-141-3p, Notch2, Bcl-2, Bax and cleaved caspase-3 were assessed by qRT-PCR or Western blot. MiR-141-3p expression was upregulated in the HUVECs isolated from PE tissues and hypoxia-induced HUVECs. Hypoxia treatment inhibited viability, tube formation, migration, and invasion, and promoted apoptosis in HUVECS, as well as increased Bax and cleaved caspase-3 expressions and decreased Bcl-2 expression. Downregulating miR-141-3p expression promoted viability, tube formation, migration and invasion, and inhibited apoptosis in HUVECs, counteracting the effect of hypoxia on HUVECs. MiR-141-3p directly targeted Notch2. Silencing Notch2 reversed the promoting effect of downregulated miR-141-3p expression on HUVECs. In conclusion, downregulating miR-141-3p expression during hypoxia promotes tube formation, migration, and invasion and inhibits apoptosis in HUVECs by targeting Notch2.

Upregulation of histone H3K9 methylation in fetal endothelial cells from preeclamptic pregnancies.

Adverse intrauterine environment has been considered a predisposing factor for fetal programming in preeclampsia. Using human umbilical vein endothelial cells (HUVECs), we specifically explored if aberrant histone methylation occurs in fetal endothelial cells in preeclampsia. Strikingly, we found that increased di-, and tri-methylation of histone H3 lysine 9 (H3K9me2 and H3K9me3) expression were associated with upregulation of methyltransferase G9a and downregulation of endothelial nitric oxide synthase and CuZn-SOD expression in preeclamptic HUVECs. We further demonstrated that hypoxia-induced hypermethylation of H3K9 and reduced CuZn-SOD expression mimicked what were seen in preeclamptic HUVECs and inhibition of G9a could attenuate these hypoxia-induced adverse events. Our study was the first to identify hypermethylation status in fetal endothelial cells in preeclampsia, which provides plausible evidence that increased oxidative stress in the intrauterine environment is likely a mechanism to induce aberrant histone modification in fetal endothelial cells which may have a significant impact on fetal programming in preeclampsia.

Circ_0063517 acts as ceRNA, targeting the miR-31-5p-ETBR axis to regulate angiogenesis of vascular endothelial cells in preeclampsia

AimsAccumulated evidence indicates that the dysregulation of circular RNAs (circRNAs) plays pivotal roles in many human diseases including preeclampsia (PE). Circ_0063517 has been verified to be down-regulated in PE. But the role of circ_0063517 in PE is still unclear. This research aims to probe into the effect of circ_0063517 on angiogenesis in PE development. Main methodsThe expression of circ_0063517, endothelin receptor type B (ETBR) and miR-31-5p was assessed by quantitative reverse transcription polymerase chain reaction (RT-qPCR). MTT assay, colony formation assay, scratch assay, transwell assay, and tube formation assay were performed to detect proliferation, migration, and angiogenesis, respectively. Dual luciferase reporter system and RNA immunoprecipitation (RIP) assay were carried out to determine the interaction between miR-31-5p and circ_0063517(or ETBR). ETBR, VEGFRA, and VEGFR2 levels were detected by western blot analysis. The effect of circ_0063517 and ETBR on angiogenesis was evaluated in N-nitro-L-arginine methyl ester hydrochloride (L-NAME)-induced PE in vivo. Key findingsThe levels of circ_0063517 and ETBR were down-regulated in the placenta tissue of PE patients. Conversely, the level of miR-31-5p was up-regulated in PE. Overexpression of circ_0063517 or knockdown of miR-31-5p facilitated growth, migration, and angiogenesis of vascular endothelial cells. Circ_0063517 knockdown-induced repression of the expression of ETBR, VEGFA, and VEGFR2 was partly counteracted by ETBR overexpression. Mechanistically, circ_0063517 sponged miR-31-5p to regulate ETBR expression. Finally, circ_0063517 promoted angiogenesis via enhancing ETBR expression in PE in vivo. SignificanceOur findings suggest that circ_0063517-miR-31-5p-ETBR axis regulates angiogenesis during the pathological process of PE.

Early-onset preeclampsia, plasma microRNAs, and endothelial cell function

Preeclampsia is a hypertensive pregnancy disorder in which generalized systemic inflammation and maternal endothelial dysfunction are involved in the pathophysiology. MiRNAs are small noncoding RNAs responsible for post-transcriptional regulation of gene expression and involved in many physiological processes. They mainly downregulate translation of their target genes. We aimed to compare the plasma miRNA concentrations in preeclampsia, healthy pregnant women, and nonpregnant women. Furthermore, we aimed to evaluate the effect of 3 highly increased plasma miRNAs in preeclampsia on endothelial cell function invitro. We compared 3391 (precursor) miRNA concentrations in plasma samples from early-onset preeclamptic women, gestational age-matched healthy pregnant women, and nonpregnant women using miRNA 3.1. arrays (Affymetrix) and validated our findings by real-time quantitative polymerase chain reaction. Subsequently, endothelial cells (human umbilical vein endothelial cells) were transfected with microRNA mimics (we choose the 3 miRNAs with the greatest fold change and lowest false-discovery rate in preeclampsia vs healthy pregnancy). After transfection, functional assays were performed to evaluate whether overexpression of the microRNAs in endothelial cells affected endothelial cell function invitro. Functional assays were the wound-healing assay (which measures cell migration and proliferation), the proliferation assay, and the tube-formation assay (which assesses formation of endothelial cell tubes during the angiogenic process). To determine whether the miRNAs are able to decrease gene expression of certain genes, RNA was isolated from transfected endothelial cells and gene expression (by measuring RNA expression) was evaluated by gene expression microarray (Genechip Human Gene 2.1 ST arrays; Life Technologies). For the microarray, we used pooled samples, but the differently expressed genes in the microarray were validated by real-time quantitative polymerase chain reaction in individual samples. No significant differences (fold change <-1.2 or >1.2 with a false-discovery rate <0.05) were found in miRNA plasma concentrations between healthy pregnant and nonpregnant women. The plasma concentrations of 26 (precursor) miRNAs were different between preeclampsia and healthy pregnancy. The 3 miRNAs that were increased with the greatest fold change and lowest false-discovery rate in preeclampsia vs healthy pregnancy were miR-574-5p, miR-1972, and miR-4793-3p. Transfection of endothelial cells with these miRNAs in showed that miR-574-5p decreased (P<.05) the wound-healing capacity (ie, decreased endothelial cell migration and/or proliferation) and tended (P<.1) to decrease proliferation, miR-1972 decreased tube formation (P<.05), and also tended (P<.1) to decrease proliferation, and miR-4793-3p tended (P<.1) to decrease both the wound-healing capacity and tube formation invitro. Gene expression analysis of transfected endothelial cells revealed that miR-574-5p tended (P<.1) to decrease the expression of the proliferation marker MKI67. We conclude that in the early-onset preeclampsia group in our study different concentrations of plasma miRNAs are present as compared with healthy pregnancy. Our results suggest that miR-574-5p and miR-1972 decrease the proliferation (probably via decreasing MKI67) and/or migration as well as the tube-formation capacity of endothelial cells. Therefore, these miRNAs may be antiangiogenic factors affecting endothelial cells in preeclampsia.

SIRT1 inhibits releases of HMGB1 and HSP70 from human umbilical vein endothelial cells caused by IL-6 and the serum from a preeclampsia patient and protects the cells from death.

Preeclampsia (PE), a pregnancy-specific disorder, is associated with inappropriate maternal inflammatory response, oxidative stress, and vascular endothelial cell dysfunction and damage. Releases of high mobility group box-1 (HMGB1) and heat-shock protein 70 (HSP70) into serum are considered to participate in the pathogenesis of PE. The deacetylase, sirtuin 1 (SIRT1), has protective effects against inflammation, apoptosis, and oxidative stress in various pathological conditions. We established a PE mouse model by injection of phosphatidylserine/dioleoyl-phosphatidycholine compounds, followed by measurement of the SIRT1 protein level in the placenta via Western blotting and the serum HMGB1 and HSP70 concentrations via enzyme-linked immunosorbent assay (ELISA). SIRT1 was down-regulated in the placenta of PE mice, in accompany with increased serum HMGB1 and HSP70 concentrations. We incubated human umbilical vein endothelial cells (HUVECs) with IL-6 and the serum from a PE patient individually to mimic status of vein endothelial cells in PE. Western blot and Immunofluorescent assays showed that HMGB1 and HSP70 protein levels were decreased in the cells, but they were increased in the cell medium based on ELISA. These suggested that HMGB1 and HSP70 were forced to be released from the cells. SIRT1 knockdown promoted the releases of HMGB1 and HSP70, whereas its over-expression inhibited the releases. Moreover, SIRT1 protected the cells from death. Collectively, SIRT1 inhibits the releases of HMGB1 and HSP70 from HUVECs caused by IL-6 and the serum from PE patient and protects the cells from death, thus SIRT1 is probably a potentially protective factor in placenta against PE.

Putative Key Role of Inositol Messengers in Endothelial Cells in Preeclampsia

Immunological alterations, endothelial dysfunction, and insulin resistance characterize preeclampsia. Endothelial cells hold the key role in the pathogenesis of this disease. The signaling pathways mediating these biological abnormalities converge on PKB/Akt, an intracellular kinase regulating cell survival, proliferation, and metabolism. Inositol second messengers are involved in metabolic and cell signaling pathways and are highly expressed during preeclampsia. Intracellular action of these molecules is deeply affected by zinc, manganese, and calcium. To evaluate the pathophysiological significance, we present the response of the intracellular pathways of inositol phosphoglycans involved in cellular metabolism and propose a link with the disease.

Placental lipase expression in pregnancies complicated by preeclampsia: a case-control study.

BackgroundPreeclampsia (PE) is associated with maternal and neonatal morbidity and mortality. In PE, the physiological hyperlipidaemia of pregnancy is exaggerated. The purpose of this study was to examine the expression of adipose triglyceride lipase (ATGL), hormone sensitive lipase (HSL), lipoprotein lipase (LPL) and endothelial lipase (EL) in pregnancies complicated by PE.MethodsPlacentae were collected from 16 women with PE and 20 women with uncomplicated pregnancies matched for maternal prepregnancy BMI and gestational age of delivery. Gene and protein expression of the placental lipases were measured by Q-PCR and Western blot. DNA methylation of the promoter of LPL was assessed by bisulfite sequencing. Lipase localisation and activity were analysed.ResultsGene expression of all lipases was significantly reduced, as was HSL protein level in women with PE. All lipases were localised to trophoblasts and endothelial cells in PE and control placentae. There was no difference in methylation of the LPL promoter between PE and control placentae. Lipase activity was not altered in placentae from women with PE.ConclusionThese results suggest that the decreased placental lipase gene but not protein expression or lipase activity, which is associated with late-onset PE is not a major contributor to the abnormal lipids seen in PE.

Relationship between insulin resistance and circulating endothelial cells in pre-eclampsia

Endothelial dysfunction and insulin resistance (IR) are established features of pre-eclampsia, however the cause and effect relationship between them remain unexplained. Circulating endothelial cells (CEC) are increased in pre-eclampsia and appear to correlate with the degree of endothelial dysfunction. We hypothesised that CEC count in pre-eclampsia would correlate with IR and might provide a simple measure of IR in pregnancies complicated by the disease. CEC count and IR were measured in 10 women with pre-eclampsia and 10 normal pregnant controls matched for maternal age, body mass index and gestational age during the third trimester. CEC count was determined using an established immunomagnetic bead separation method and IR was measured by the homeostasis model test. CEC count and IR were significantly increased in pre-eclampsia compared to normal pregnancy. However, there was no correlation between the CEC count and IR in pre-eclampsia. The data suggest that CEC count in pre-eclampsia is not a useful measure on its own of IR in pregnancies complicated by the disease.

Neutrophil-derived Reactive Oxygen Species Can Modulate Neutrophil Adhesion to Endothelial Cells in Preeclampsia

Neutrophil activation has been implicated in the pathophysiology of preeclampsia. The aim of this study was to investigate whether neutrophil-derived reactive oxygen species (ROS) modulate adhesion to endothelial cells in preeclampsia. We first assessed neutrophil superoxide production and neutrophil-endothelial cell adhesion in normal nonpregnant women (n = 8), normal pregnant women (n = 10), and preeclamptic pregnant women (n = 8). We then examined the effects of neutrophil-derived ROS on neutrophil-endothelial adhesion. The release of neutrophil superoxide was measured using cytochrome C reduction. N-formyl-methionyl-leucyl-phenylalanine (FMLP)-stimulated superoxide production by neutrophils was significantly increased in women with preeclampsia when compared with the other two groups. Neutrophils from women with preeclampsia were more likely to adhere to endothelial cells, than were those from the other two groups (mean adhesion rate +/- s.d. (%); 20.6 +/- 2.7 in preeclampsia, 10.2 +/- 1.2 in normal pregnancy, 11.0 +/- 0.9 in normal nonpregnancy, P < 0.01). Superoxide dismutase (SOD), which dismutates the excess superoxide to hydrogen peroxide, did not affect neutrophil-endothelial adhesion. In contrast, catalase, which catalyzes the conversion of hydrogen peroxide to oxygen and water, inhibited neutrophil-endothelial adhesion in the preeclamptic group (8.1 +/- 0.5%, P < 0.01). Neutrophils from women with preeclampsia demonstrate increased CD11b expression and adhesion to endothelial cells. This is likely caused by elevations in superoxide and its derivative, hydrogen peroxide.

Circulating endothelial cells in preeclampsia

Endothelial dysfunction plays an important role in the pathogenesis of preeclampsia. Increased number of circulating endothelial cells (CECs) have previously been reported after various diseases associated endothelial injury. The aim of this study was to evaluate the CECs in patients with preeclampsia and to demonstrate any association between CECs and homocysteine, which is another marker of vascular injury. The study included 20 preeclamptic, 15 hypertensive women, 15 healthy pregnant and 15 healthy non-pregnant women. All subjects had normal renal function. Systolic and diastolic blood pressures, serum homocysteine levels were measured. To isolate CECs, peripheral blood was first incubated with anti-CD-146 antibody and subsequently conjugated to immunomagnetic beads. Cells were stained with acridine and counted. Preeclamptic patients had elevated numbers of CECs (13.2+/-5.2 cells/ml) compared with hypertensive patients (6.9+/-0.8 cells/ml), healthy pregnants (5.2+/-1.4 cells/ml), and non-pregnant controls (4.0+/-1.8 cells/ml), (P<0.0001). Serum homocysteine level in preeclamptic patients (9.5+/-2.8 micromol/l) was significantly higher compared with healthy pregnants (6.0+/-0.6 micromol/l), was not different from hypertensive patients (11.5+/-2.3 micromol/l, P>0.05), but it was lesser compared with non-pregnant controls (12.2+/-3.3 micromol/l, P<0.0001). Also, significant correlation between CECs and systolic blood pressure (P<0.0001, r=0.63), diastolic blood pressure (P<0.0001, r=0.64) and serum homocysteine (P<0.01, r=0.55) levels were found in preeclamptic patients. CECs as a marker of endothelial injury were significantly higher in patients with preeclampsia than in hypertensive patients, healthy pregnants and normal controls. Further studies are needed for the prognostic and potential importance of CECs in preeclampsia.

Pathogenetic Role of Mature and Progenitor Endothelial Cells in Pre-Eclampsia.

Pre-eclampsia (PE) is a pregnancy-associated disorder of unknown cause. The pathological changes associated with PE (edema, proteinuria, coagulopathy, and renal and hepatic abnormalities) suggest a systemic maternal vascular dysfunction. PE is also associated with placental development defects and fetal growth restriction.The generation of vessels is divided into angiogenesis (the sprouting of capillaries from pre-existing vessels) and vasculogenesis, the development of blood vessels from in situ differentiating endothelial cells (ECs), which has been considered as occurring only in the prenatal period. However, circulating endothelial precursors (CEPs) are also present in the peripheral blood (PB) of adults and, in the case of pregnant women, may play important roles in vascularising the uterine endometrium at the time of embryo implantation and placentation. Furthermore, it has been found that the number of mature circulating endothelial cells (CECs) is increased in the PB of patients affected by cancer, sickle cell anemia, myocardial infarction or infections, but they have not been extensively studied in PE patients.Inorder to test the hypothesis that CEPs may be involved in the pathogenesis of PE and that CECs may represent a marker of the severity of ongoing vascular damage, we used flow cytometry to quantify the number of CEPs and CECs in 17 PE patients and 13 healthy pregnant women of similar gestational age.Immunocytofluorimetric assays showed that resting CECs were negative for CD45 but positive for P1H12 and CD31, whereas CEPs were positive for CD133 and CD34. Our 13 healthy controls had a mean number of 20.8 CECs/ml (range 9.22–77.11) and 1.05 CEPs/ml (range 0.07–3.43); the corresponding numbers in 27 samples from the 17 PE cases were 25.46/ml (range 1.65–126.34) and 0.42/ml (range 0–15.45). The PE cases had significantly fewer CEPs than the controls (p <0.05, Mann-Whitney test). Among the PE cases, we compared the samples collected during severe (16 samples) and mild PE (11 samples): the severe PE group showed significantly more CECs than the mild PE group (29.03/ml [range 1.65–120.78] vs 13.58/ml [range 7.67–126.34; p <0.02, Mann-Whitney test) but not CEPs (0.51/ml [range 0–15.45] vs 0.23/ml [range 0–1.41]). In conclusion, there is a reduction in CEPs during PE that may be consistent with an impaired response to vascular damage. As CEPs seem to play a crucial role in the vasculogenesis of the placental bed during pregnancy, this finding is consistent with the fetal growth restriction and placental maturation defects observed during pregnancy. Furthermore, the women with severe PE had more CECs (a marker of ongoing endothelial damage) than those with mild PE. Our findings are consistent with the hypothesis that PE is characterised by a systemic maternal vascular dysfunction, with reduced repair potential (fewer CEPs), and the increased number of CECs in the peripheral blood of women with severe PE correlates with disease severity. Further longitudinal studies are needed to verify their prognostic role.

Effect of sera on the adhesion of natural killer cells to the endothelium in severe pre‐eclampsia

To investigate the effect of serum on the interaction between natural killer (NK) cells and endothelial cells in pre-eclampsia. Seven severely pre-eclamptic patients, five normal pregnant women, and four normal non-pregnant women were included in this study. Freshly isolated NK cells labeled with Chromium-51 were incubated on an endothelial cell monolayer in the presence of patient serum. In regard to the characteristics of adhesive molecules, the endothelial cells were blocked by monoclonal antibodies (mAbs) to intracellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1); the NK cells were blocked by mAbs to leukocyte function-associated antigen (LFA-1) and very late antigen-4 (VLA-4) before co-incubation. After incubation, the adherent cells were solubilized with 1% Triton X. The lysates were collected and counted in a gamma counter. The adhesion of NK cells to the endothelium in the normal pregnancy group decreased significantly in comparison to the non-pregnant group (7%vs 72%; P < 0.01). Adhesion in the severe pre-eclamptic group was significantly higher in comparison to the normal pregnant group (44%vs 7%; P < 0.01). The blocking percentages of mAbs on NK adhesion in the severe pre-eclampsia group were 49 +/- 4% to LFA-1, 61 +/- 48%, 67 +/- 39% to VLA-4, ICAM-1, and 68 +/- 7% to VCAM-1. Sera from normal pregnant women suppress the adhesion between NK cells and endothelial cells, whereas the suppressive effect of sera from pre-eclamptic patients has a diminished affect.

Genetic origin and proportion of basal plate surface cells in normal and abnormal pregnancies

The basal plate of the placenta is the floor of the intervillous space. The cellular constituents of the basal plate surface that are in direct contact with maternal blood include trophoblasts (TB; of fetal origin) and endothelial cells (EC) whose origin (fetal or maternal) is unknown. This study was conducted to 1) determine the origin of these EC; and 2) to assess the relative proportion of TB and EC covering the intervillous surface of the basal plate in placentas from normal and preeclamptic pregnancies. Placentas from patients with normal term gestations (n = 9) and preeclampsia (n = 10) were included. Five sections of the basal plate were obtained from the central, paracentral and peripheral regions of each placenta. Double immunohistochemistry (vimentin: EC and cytokeratin 7: TB) and image analysis were performed. Seven placentas of male fetuses were used to evaluate the origin of the EC. Genomic DNA isolated from laser microdissected EC was subjected to PCR for sex typing. Data were analyzed using non-parametric statistics. 1) The median proportion of TB and EC covering the basal plate surface in normal placentas was 8% (range 6.5-17.6%) and 13.6% (range: 4.4-24.6%), respectively; 2) the median TB/EC ratio was 0.8 (range: 0.3-4); 3) in preeclampsia, the basal plate surface showed a higher proportion of TB than those from normal pregnancies (median: 17.6%, range: 5.9-29.2%, p = 0.04); 4) a trend towards a lower proportion of EC in preeclampsia was observed; and 5) EC covering the basal plate were of maternal origin. 1) For the first time, EC lining the intervillous space surface of the basal plate have been identified to be of maternal origin; and 2) preeclampsia is associated with an excess of TB covering the surface of the basal plate.

Hypertension During Pregnancy

Hypertension during pregnancy remains a common and potentially devastating complication.1,2 Hypertension can be isolated (gestational hypertension) or associated with proteinuria (preeclampsia) and, rarely, can manifest as a consequence of either preexisting or new onset renal (usually glomerular) disease. Preeclampsia is a particularly worrisome diagnosis, because it carries increased risk for morbidity to the mother and child and may accelerate to the condition of eclampsia in which seizures develop in association with a high risk for fetal and maternal mortality. Although, ideally, the diagnosis of these conditions should involve the use of biomarkers that reflect the underlying pathophysiology of the disease process, the lack of clinically available assays has forced the clinician to diagnose the condition based solely on the clinical presentation. Unfortunately, although establishing cut points for elevated blood pressure and urine protein excretion appears to be straightforward, these continuous variables lend themselves to arbitrary definitions, and this likely explains why the precise definition of preeclampsia has changed several times and why different organizations continue to classify preeclampsia differently.3 A recent report from the National High Blood Pressure Education Program Working Group on High Blood Pressure in Pregnancy3 nicely summarized the current status of diagnosing preeclampsia: “Although our current understanding of this syndrome has increased, the criteria used to identify the disorder remain subject to confusion and controversy. The confusion doubtless reflects the fact that preeclampsia is a syndrome, which means that attempts at definition use arbitrarily selected markers rather than changes of pathophysiologic importance.” Adding to this confusion is the fact that a …

Heme oxygenase expression in human placenta and placental bed: reduced expression of placenta endothelial HO-2 in preeclampsia and fetal growth restriction.

In this study we tested the hypothesis that expression of heme oxygenases HO-1 and HO-2, which are responsible for the production of carbon monoxide, are reduced in the placenta and placental bed of pregnancies complicated by preeclampsia (PE) and fetal growth restriction (FGR) compared with control third-trimester pregnancies. Placental protein expression was determined by Western blotting (n=10 in each group) and immunohistochemistry (controls n=18, PE n=19, FGR n=10). Extravillous trophoblast expression was determined by immunohistochemistry of placental bed biopsy samples (controls n=17, PE n=19, FGR n=10). Western blot analysis of placental homogenates showed no overall differences in HO-2 among groups. However, immunohistochemical analysis showed a reduction in HO-2 expression in endothelial cells in both abnormal groups (PE P<0.01; FGR P<0.0005 vs. control group) but no differences in villous trophoblast staining. HO-1 was undetectable by Western blotting in control and abnormal pregnancies and immunoreactivity was very low, suggesting that there is little HO-1 in the placenta. Within the placental bed, HO-2 but not HO-1 was detected on all populations of extravillous trophoblast, but expression of HO-2 or HO-1 did not change in PE or FGR. The reduced expression of HO-2 on endothelial cells in PE and FGR may be responsible for reduced placental blood flow in these conditions. The data do not show changes in HO in the placental bed in PE or FGR.

Activation of Endothelial Cells in Preeclampsia: Increased Neutrophil-Endothelial Adhesion Correlates With Up-regulation of Adhesion Molecule P-selectin in Human Umbilical Vein Endothelial Cells Isolated From Preeclampsia

Activation of Endothelial Cells in Preeclampsia: Increased Neutrophil-Endothelial Adhesion Correlates With Up-regulation of Adhesion Molecule P-selectin in Human Umbilical Vein Endothelial Cells Isolated From Preeclampsia

Activation of endothelial cells in preeclampsia: increased neutrophil-endothelial adhesion correlates with up-regulation of adhesion molecule P-selectin in human umbilical vein endothelial cells isolated from preeclampsia.

Increased endothelial activation has been suggested to be important in the pathophysiology for preeclampsia. Our objective was to examine whether in preeclampsia neutrophil adherence to endothelial cells is increased and whether endothelial cell-surface adhesion molecule expression is up-regulated. Endothelial cells were isolated from normal (n = 10) and preeclamptic (n = 9) human umbilical veins (HUVECs). Neutrophils were isolated from normal, healthy, nonpregnant female volunteers. Freshly isolated neutrophils were labeled with 51Cr, and labeled neutrophils were coincubated with confluent normal and preeclamptic endothelial monolayers. Adhesion assays were then performed. To determine whether in preeclampsia endothelial cellular-surface adhesion molecules are responsible for increased neutrophil-endothelial adhesion, cellular adhesion molecule expression of P-selectin, intercellular adhesion molecule-1 (ICAM-1), vascular cellular adhesion molecule-1 (VCAM-1), and E-selectin were examined by an enzyme-linked binding assay. Furthermore, adhesion assays were also performed on HUVECs pretreated with antibodies against P-selectin, ICAM-1, VCAM-1, and E-selectin. Neutrophil adhesion to the HUVECs from preeclamptic pregnancies was significantly increased compared with neutrophil adhesion to the HUVECs from normal pregnancies (P < .01). Expression of cellular-surface adhesion molecule of P-selectin was significantly higher (P < .01) and ICAM-1 was significantly lower (P < .05) in HUVECs isolated from preeclampsia than from normal controls, whereas there was no difference for VCAM-1 and E-selectin expression between HUVECs from normal and preeclamptic pregnancies. No differences were found for neutrophil-endothelial adhesion on normal HUVECs pretreated with anti-P-selectin, anti-ICAM-1, anti-VCAM-1, and anti-E-selectin compared with the untreated cells. However, pretreatment of preeclampsia HUVECs with anti-P-selectin, anti-ICAM-1, anti-VCAM-1, and anti-E-selectin completely or partially blocked the neutrophil-endothelial adhesion compared to the untreated cells. There is a significant increase in neutrophil adhesion to HUVECs that are isolated from preeclamptic pregnancies compared with normal controls. This increase appears to be a result of up-regulation of the cell-surface adhesion molecule P-selectin. Elevated P-selectin expression may play a significant role in neutrophil-endothelial hyperadhesiveness and contribute to vascular complications associated with preeclampsia.

The calcium-dependent nitric oxide production of human vascular endothelial cells in preeclampsia

OBJECTIVE: Nitric oxide is an important vasodilator, and in this study we studied whether the calcium-dependent nitric oxide production capacity of human umbilical vein endothelial cells was affected by preeclampsia. STUDY DESIGN: Human umbilical vein endothelial cells were isolated from 11 preeclamptic and 10 normotensive pregnancies. The maximal calcium ionophore A23187-stimulated nitric oxide production capacity was measured as accumulation of nitrate and nitrite into the culture medium, and it was related to the number of viable endothelial cells by measurement of their mitochondrial dehydrogenase activity. RESULTS: The cell number - related nitric oxide production capacity was similar in preeclamptic and normotensive pregnancies. The total nitric oxide production of cells from preeclamptic pregnancies was significantly lower ( p < 0.001). This difference, however, was mainly caused by larger amount of viable endothelial cells recovered from normotensive pregnancies. CONCLUSION: The maximal calcium-dependent nitric oxide production capacity of individual human umbilical vein endothelial cells is not affected by preeclampsia. (A M J O BSTET G YNECOL 1996;174:1056-60.)

Serum Collagen IV and Laminin Levels in Preeclampsia

Collagen IV is the main collagenous component localized in the trophoblast and glomerular basement membrane. Serum collagen V reflects degradation of basement membrane collagen. In this study, we measured collagen IV levels in maternal serum, umbilical cord serum and amniotic fluid, both from preeclamptic and normal pregnant women, by radioimmunoassay. The serum collagen IV levels in the preeclamptic group were significantly (p < 0.05) higher than those in the normal pregnant group. The amniotic fluid collagen IV level at term was found to be higher than maternal serum collagen IV. We postulate that collagen IV may have an important role in the maintenance of pregnancy. There was a significant positive correlation between maternal serum collagen IV levels and serum laminin levels. There was no significant correlation between maternal serum collagen IV level and blood pressure, urinary protein concentration, or any other laboratory data. These results suggest that there is early damage of endothelial cells in preeclampsia.