Effect of antihypertensive therapy with alpha methyldopa on levels of angiogenic factors in pregnancies with hypertensive disorders

Longitudinal Associations between Ambient Air Pollution and Angiogenic Biomarkers among Pregnant Women in the LIFECODES Study, 2006-2008

BACKGROUND

Exposures to ambient air pollution during pregnancy have been linked to adverse pregnancy outcomes such as preeclampsia and fetal growth restriction. Although evidence has shown that women with preeclampsia have higher ratio of soluble fms-like tyrosine kinase 1 to placental growth factor (sFlt-1/PlGF ratio), the potential impact of air pollution on markers of placental growth and function has not been well studied.

OBJECTIVES

We aimed to examine longitudinal associations between ambient air pollution exposure and angiogenic factors among pregnant women in LIFECODES, a prospective birth cohort and biorepository in Massachusetts in the United States.

METHODS

PlGF and sFlt-1 were measured among pregnant women using plasma samples collected around 10, 18, 26, and 35 wk' gestation. Women's exposures to ozone (O 3 ), fine particulate matter with aerodynamic diameter ≤ 2.5 μ m (PM 2.5 ), and nitrogen dioxide (NO 2 ) within 1, 2, 4, and 8 wk prior to each plasma sample collection were estimated based on geocoded residential addresses, and mixed effect linear regression models were fitted to assess their associations with sFlt-1/PlGF ratio, sFlt-1 (ng/mL), and PlGF (pg/mL). Percent changes in outcomes associated with each interquartile range increase in exposures were reported, along with their 95% confidence intervals.

RESULTS

A total of 1,066 pregnant women were included. In the multipollutant models, significant associations were observed for increased sFlt-1/PlGF ratio (PM 2.5 3-8 wk' gestation, NO 2 : 35-39 wk' gestation), elevated sFlt-1 (O 3 : 26-34 wk' gestation, PM 2.5 : 3-8 wk' gestation), decreased sFlt-1 (NO 2 : 4-8 wk' gestation), and decreased PlGF (NO 2 : 34-39 wk' gestation) after adjusting for sociodemographic status, smoking, drinking, body mass index, parity, history of chronic hypertension, and conception time.

DISCUSSION

Exposures to PM 2.5 during early pregnancy and exposures to O 3 and NO 2 during late pregnancy were associated with increased sFlt-1/PlGF ratio, elevated sFlt-1 and with decreased PlGF, which may be a potential mechanism underlying ambient air pollution's impacts on adverse pregnancy and birth outcomes. https://doi.org/10.1289/EHP11909.

New Ideas for the Prevention and Treatment of Preeclampsia and Their Molecular Inspirations

Preeclampsia (PE) is a pregnancy-specific disorder affecting 4-10% of all expectant women. It greatly increases the risk of maternal and foetal death. Although the main symptoms generally appear after week 20 of gestation, scientific studies indicate that the mechanism underpinning PE is initiated at the beginning of gestation. It is known that the pathomechanism of preeclampsia is strongly related to inflammation and oxidative stress, which influence placentation and provoke endothelial dysfunction in the mother. However, as of yet, no "key players" regulating all these processes have been discovered. This might be why current therapeutic strategies intended for prevention or treatment are not fully effective, and the only effective method to stop the disease is the premature induction of delivery, mostly by caesarean section. Therefore, there is a need for further research into new pharmacological strategies for the treatment and prevention of preeclampsia. This review presents new preventive methods and therapies for PE not yet recommended by obstetrical and gynaecological societies. As many of these therapies are in preclinical studies or under evaluation in clinical trials, this paper reports the molecular targets of the tested agents or methods.

Polymeric and Composite Carriers of Protein and Non-Protein Biomolecules for Application in Bone Tissue Engineering

Conventional intake of drugs and active substances is most often based on oral intake of an appropriate dose to achieve the desired effect in the affected area or source of pain. In this case, controlling their distribution in the body is difficult, as the substance also reaches other tissues. This phenomenon results in the occurrence of side effects and the need to increase the concentration of the therapeutic substance to ensure it has the desired effect. The scientific field of tissue engineering proposes a solution to this problem, which creates the possibility of designing intelligent systems for delivering active substances precisely to the site of disease conversion. The following review discusses significant current research strategies as well as examples of polymeric and composite carriers for protein and non-protein biomolecules designed for bone tissue regeneration.

Atypical Preeclampsia before 20 Weeks of Gestation-A Systematic Review

This systematic review was conducted to gather evidence of preeclampsia occurring before the 20th week of gestation, additionally considering the role of PLGF and sFlt-1 in the development of the disease. In the three cases of preeclampsia before the 20th week of gestation presented in the authors' material, all pregnancies ended up with IUFD, and the SFlt-1/PLGF ratios were significantly elevated in all women. Eligible publications were identified with searches in the PubMed, Embase, Scopus, and Web of Science databases. No date or language restrictions were made. All original peer-reviewed scientific reports were included. A total of 30 publications were included in the final report, including case reports and case series. No other publication types regarding this issue were identified. In the literature, 34 cases of preeclampsia with onset occurring before the 20th week of gestation were identified, for a final total of 37 cases. Live births were reported in 5 cases (10.52%), and there were 9 intrauterine fetal demises (24.32%), and 23 terminations of pregnancy (62.16%). Preeclampsia before the 20th week of gestation is rare but can occur. We collected all available evidence regarding this phenomenon, with 37 cases reported worldwide. We call for large-scale cohort or register-based studies to establish revised definitions or develop new ones regarding the currently unrecognized very early onset preeclampsia.

A prospective and comparative investigation of blood sFlt-1, P1GF, and niacin concentrations in women with premature ovarian insufficiency

OBJECTIVE

Endothelial dysfunction is an important component of preeclampsia like premature ovarian insufficiency (POI), and it is reported that placental growth factor (P1GF) and soluble fms-like tyrosine kinase receptor-1 (sFlt-1) levels are important in preeclampsia. Extra-placental sources for P1GF and sFlt-1 have also been identified, including various cell types. In animal models of POI, niacin treatment inhibited follicular apoptosis under hazardous conditions while significantly reducing cumulus cell apoptosis. The number of developing follicles also increased after niacin was given. This study was designed to determine blood sFlt-1, P1GF, and niacin concentrations in women with idiopathic POI (iPOI) compared with those of healthy women.

METHODS

The study comprised 45 women with iPOI and 45 healthy women. Blood was obtained and analyzed at the early follicular phase of the menstrual cycle and sFlt-1, P1GF, and niacin levels were measured using a commercially available enzyme-linked immunosorbent assay kit.

RESULTS

No significant differences were observed in the two groups according to the gravidity numbers, parity, abortion, live births, and menarche ages (p ≥ 0.05). In the iPOI group, the mean anti-mullerian hormone value was 0.03 ± 0.04 (min-max, 0.00-0.21) ng/ml. sFlt-1, P1GF, niacin levels, and also the sFlt-1/P1GF ratio were lower in the iPOI group (p < 0.01). A significant discriminative role of sFlt-1, P1GF, niacin levels, and the sFlt-1/P1GF ratio for the presence of iPOI, with cut-off values of 5.13, 10.28, 37.17, and 0.61 ng/ml, respectively, were reported in the receiver operating characteristics curve analysis.

CONCLUSIONS

Lower levels of P1GF, sFlt-1, niacin, and sFlt-1/P1GF ratios may be associated with the development of POI/iPOI. Further studies are required to better understand the etiopathogenesis of POI/iPOI.

CLINICAL TRIAL NUMBER

NCT04641624 (clinicaltrials.gov).

Non-invasive diagnosis of endometriosis: Immunologic and genetic markers

Endometriosis, a benign gynecologic and chronic inflammatory disease, is defined by the presence of endometrial tissue outside the uterus characterized mainly by pelvic pain and infertility. Because endometriosis affects approximately 10% of females, it represents a significant socioeconomic burden worldwide having tremendous impact on daily quality of life. Accurate and prompt diagnosis is crucial for the management of this debilitating disorder. Unfortunately, diagnosis is typically delayed to lack of specific symptoms and readily accessible biomarkers. Although histopathologic examination remains the current gold standard, this approach is highly invasive and not applicable for early screening. Recent work has focused on the identification of reliable biomarkers including immunologic, ie, immune cells, antibodies and cytokines, as well as genetic and biochemical markers, ie, microRNAs, lncRNAs, circulating and mitochondrial nucleic acids, along with some hormones, glycoproteins and signaling molecules. Confirmatory research studies are, however, needed to more fully establish these markers in the diagnosis, progression and staging of these endometrial lesions.

Combined Effects of Methyldopa and Baicalein or Scutellaria baicalensis Roots Extract on Blood Pressure, Heart Rate, and Expression of Inflammatory and Vascular Disease-Related Factors in Spontaneously Hypertensive Pregnant Rats

The aim of the study was to investigate the effect of baicalein or Scutellaria baicalensis root extract interaction with methyldopa in pregnant spontaneously hypertensive rats (SHR) at the pharmacodynamic, molecular, and biochemical levels. The rats, after confirming pregnancy, received baicalein (200 mg/kg/day, p.o.) and extract (1000 mg/kg/day, p.o.), in combination with methyldopa (400 mg/kg/day; p.o.), for 14 consecutive days, 1 h before blood pressure and heart rate measurements. In the heart and placenta from mothers after giving birth to their offspring, mRNA expression of factors related to inflammatory processes (TNF-α, Il-1β, IL-6) and vascular diseases (TGF-β, HIF-1α, VEGF, PlGF) was measured. Levels of markers of oxidative stress (superoxide dismutase and malondialdehyde) in the placenta and indicators of myocardial damage (troponin cTnC and cTnI, creatine kinase, myoglobin, and lactate dehydrogenase) in the heart were also assessed. Baicalein co-administered with methyldopa was associated with reduced blood pressure, especially during the first three days. The interactions were more pronounced for such factors as TGF-β, HIF-1α, VEGF, and PlGF than TNF-α, Il-1β, and IL-6. Combined application of baicalein and extract with methyldopa may be of value in the development of a new antihypertensive medication intended for patients suffering from preeclampsia or pregnancy-induced hypertension.

A STUDY ON THE CORRELATION BETWEEN THE ENDOTHELIN-1, NITRIC OXIDE FUNCTION AND THE RENAL HEMODYNAMICS IN PATIENTS WITH HYPERTENSIVE DISORDERS IN PREGNANCY IN HUBEI

Objective: To analyze the correlation between the vascular endothelial function (characterized by endothelin-1 and nitric oxide) and the renal hemodynamics in patients with hypertensive disorders in pregnancy (HDP) by color Doppler ultrasound.

Method: Depending on the severity of the disease, 76 HDP patients were divided into three groups, namely, pregnancy-induced hypertension (PIH) group ([Formula: see text]), mild preeclampsia (PE) group ([Formula: see text]), and severe PE group ([Formula: see text]). In the meantime, 28 healthy pregnant women were selected as controls. Color Doppler ultrasound was performed to determine the following parameters in the interlobar arteries of the kidney: Resistance index (RI), peak end-diastolic velocity (EDV), pulsatility index (PI), peak systolic velocity (PSV), and S/D ratio. The correlations of these parameters with the serum levels of ET-1 and NO were then analyzed.

Result: (1) In the interlobar arteries of the kidney, RI, S/D, PI were positively significantly correlated to the serum level of ET-1 in HDP patients (All [Formula: see text]) and negatively to the serum level of NO (All [Formula: see text]). (2) RI, S/D, PI of the mild and severe PE groups were significantly higher than those of the control group (All [Formula: see text]). However, EDV of the mild and severe PE groups was significantly lower than that of the control group (All [Formula: see text]). (3) The serum level of ET-1 was significantly higher in the HDP patients than in the control group ([Formula: see text]). However, the serum level of NO was significantly lower in the former than in the latter ([Formula: see text]). As HDP became more severe, there was an elevation in the serum level of ET-1 and a decrease in NO.

Conclusion: Indicators of renal hemodynamics measured by color Doppler ultrasound were correlated to the serum levels of ET-1 and NO characterizing the vascular endothelial function. They were sensitive indicators reflecting hemodynamic changes and renal impairment in HDP patients.

Placental growth factor as a diagnostic tool for placental mediated fetal growth restriction

OBJECTIVE

Placental growth factor (PlGF) has shown promise in identification of placental fetal growth restriction (FGR). We aimed to investigate the association between PlGF and sonographic markers of placental dysfunction and assess its ability to diagnose FGR secondary to maternal vascular malperfusion (MVM).

STUDY DESIGN

A retrospective study of singleton pregnancies with small for gestational age (SGA) fetuses, who had PlGF testing at 16-36 weeks. Fetuses with major chromosomal and/or structural anomalies and pregnancies with missing outcomes were excluded. Sonographic characteristics, perinatal outcomes and placental histopathology were compared between pregnancies with normal and low PlGF (<10th percentile for gestational age). The diagnostic accuracy of PlGF for prediction of MVM was calculated.

RESULTS

130 fetuses met inclusion criteria. Compared to normal PlGF (n = 65), pregnancies with low PlGF (n = 65) were associated with an estimated fetal weight < 5th centile (73.8% (48) vs 53% (35), respectively, p = 0.01), abnormal uterine, umbilical and MCA Dopplers (p = 0.001 for all), fetal demise (18.8% (12) vs 0% respectively, p = 0.01) and preterm delivery (100% (65) vs 39% (59), respectively, p < 0.001) . Low PlGF had a 70.1% (58.6-80.0) sensitivity and a 79.6% (64.7-90.2) specificity for identifying MVM, with an AUC of 0.73 (0.63-0.84). Positive and negative predictive values were 85.7% (76.8-91.2) and 60.3% (51.2-68.9), respectively. PlGF outperformed other parameters of placental FGR (uterine, umbilical artery, middle cerebral artery and abdominal circumference < 5th centile), in isolation and when combined.

CONCLUSION

PlGF is a useful tool to aid in the diagnosis of placental FGR secondary to MVM.

Syncytiotrophoblast stress in early onset preeclampsia: The issues perpetuating the syndrome

Preeclampsia is a pregnancy-specific syndrome characterized by a sudden increase in blood pressure accompanied by proteinuria and/or maternal multi-system damage associated to poor fetal outcome. In early-onset preeclampsia, utero-placental perfusion is altered, causing constant and progressive damage to the syncytiotrophoblast, generating syncytiotrophoblast stress. The latter leads to the detachment and release of syncytiotrophoblast fragments, anti-angiogenic factors and pro-inflammatory molecules into maternal circulation, resulting in the emergence and persistence of the characteristic symptoms of this syndrome during pregnancy. Therefore, understanding the origin and consequences of syncytiotrophoblast stress in preeclampsia is vital to develop new therapeutic alternatives, focused on reducing the burden of this syndrome. In this review, we describe five central characteristics of syncytial stress that should be targeted or prevented in order to reduce preeclampsia symptoms: histological alterations, syncytiotrophoblast damage, antiangiogenic protein export, placental deportation, and altered syncytiotrophoblast turnover. Therapeutic management of these characteristics may improve maternal and fetal outcomes.

Combined Effects of Methyldopa and Flavonoids on the Expression of Selected Factors Related to Inflammatory Processes and Vascular Diseases in Human Placenta Cells-An In Vitro Study

The aim of the study was to investigate combined effects of flavonoids (apigenin, baicalein, chrysin, quercetin, and scutellarin) and methyldopa on the expression of selected proinflammatory and vascular factors in vitro for prediction of their action in pregnancy-induced hypertension. The research was conducted on a trophoblast-derived human choriocarcinoma cell line and a primary human umbilical vein endothelial cell line. Cytotoxicity of compounds in selected concentrations (20, 40, and 100 µmol) was measured using the MTT test and the concentration of 40 µmol was selected for further analysis. Subsequently, their effects with methyldopa on the expression of selected markers responsible for inflammation (TNF-α; IL-1β; IL-6) and vascular effects (hypoxia-inducible factor 1α—HIF-1α; placental growth factor—PIGF; transforming growth factor β—TGF-β; vascular endothelial growth factor—VEGF) at the mRNA and protein levels were assessed. It was found that every combined administration of a flavonoid and methyldopa in these cells induced a down-regulating effect on all tested factors, except PIGF, especially at the mRNA expression level. As hypertension generally raises TNF-α, IL-1β, IL-6, HIF-1α, TGF-β, and VEGF mRNA expression and/or protein levels, the results obtained in the studied model may provide a positive prognostic factor for such activity in vivo.

Impact of Melatonin on Full-Term Fetal Brain Development and Transforming Growth Factor-β Level in a Rat Model of Preeclampsia

Preeclampsia (PE) is a leading cause of stroke and cognitive impairment in the offspring. Melatonin is involved in the outcome of normal pregnancy. Its receptors are widespread in the embryo. This study aimed to investigate the fetal neuroprotective effect of melatonin in experimentally induced PE. After induction of pregnancy in 18 female rats, they were divided into three equal groups. PE was induced in groups II and III by injection of deoxycorticosterone acetate and drinking isotonic saline. Melatonin was supplied to group III orally (10 mg/kg body weight) throughout pregnancy. Pregnancy was terminated on day 20, and macroanatomical investigation of three fetuses from each pregnant rat and their placentae was performed. Placental and brain homogenates were analyzed for malondialdehyde (MDA), placental growth factor (PLGF), tumor necrosis factor-α (TNF-α), and brain transforming growth factor-β (TGF-β). Histopathological analysis of fetal brain sections was performed. Melatonin improved placental, fetal, and brain weight; significantly reduced fetal death rate; significantly increased PLGF, placental and brain superoxide dismutase, and brain TGF-β; and significantly decreased placental TNF-α and brain MDA. Brain micromorphological study found normal glial cells and neuropil in the melatonin-treated group and a loss of neuronal cell outlines with an accumulation of cellular debris in the untreated group. In conclusion, melatonin approximately showed a neuroprotective activity by managing PE-induced oxidative stress in the placenta and fetal cerebral cortex of rats.

Use of Placental Growth Factor for Trisomy 21 Screening in Pregnancy: A Systematic Review

Background  Prenatal serum screening is an important modality to screen for aneuploidy in pregnancy. The addition of placental growth factor (PLGF) to screen for trisomy 21 remains controversial. Objective  To determine whether the addition of PLGF to combined serum aneuploidy screening improves detection rates (DRs) for trisomy 21. Study Design  We performed a systematic review of the literature until October 2019 to determine the benefits of adding PLGF to prenatal screening. We performed a goodness-of-fit test and retrieved the coefficient of determinations ( R ² ) as a function of false positive rates (FPRs), providing mean-weighted improvements in the DRs after accounting for PLGF levels. Results  We identified 51 studies, of which 8 met inclusion criteria (834 aneuploidy cases and 105,904 euploid controls). DRs were proportional to FPR across all studies, ranging from 59.0 to 95.3% without PLGF and 61.0 to 96.3% with PLGF (FPR 1-5%). Goodness-of-fit regression analysis revealed a logarithmic distribution of DRs as a function of the FPR, with R ²  = 0.109 (no PLGF) and R ²  = 0.06 (PLGF). Two-sample Kolmogorov-Smirnov's test reveals a p -value of 0.44. Overall, addition of PLGF improves DRs of 3.3% for 1% FPR, 1.7% for 3% FPR, and 1.4% for 5% FPR, respectively. Conclusion  Addition of PLGF to prenatal screening using serum analytes mildly improves trisomy 21 DRs as a function of FPRs.

Longitudinal changes in placental biomarkers in women with early versus late placental dysfunction

Objective: To evaluate longitudinal changes of angiogenic biomarkers in early- (EO-PD) versus late-onset (LO-PD) placental dysfunction. Methods: Serum PlGF and sFlt-1 measured at different intervals in EO-PD (n= 43), LO-PD (n= 31) and controls (n = 133). Results: sFlt-1/PlGF ratio was higher at 16 weeks (30.6 vs 17.5), 20 weeks (29.3 vs 8.9) and 30 weeks (16.6 vs 6.7) in EO-PD vs controls (all p< 0.05), but not in LO-PD. Longitudinal changes for all intervals had higher AUC than single measurements. Conclusion: Longitudinal biomarker change between 12 and 30 weeks could improve prediction of EO-PD compared to single measurements.

Comparison of cytokine expression and ultrastructural alterations in fresh-frozen and dried electron beam-irradiated human amniotic membrane and chorion

The purpose of the current study was to compare the effects of drying and fresh-freezing on human amniotic membrane (HAM) and amnion/chorion membrane (HACM) in terms of histological and structural characteristics and cytokine levels. HAM and HACM samples, obtained from six placentae, were investigated. HAM and HACM were dried, electron beam-irradiated (dehydration group; d-HAM/d-HACM), or fresh-frozen (freezing group; f-HAM/f-HACM). Luminex assay was used to assay the levels of 15 cytokines. The ultrastructural characteristics of HAM and HACM were evaluated using light and transmission electron microscopies. Total cytokine contents did not show the statistical difference between dehydration and fresh-freezing process. Significantly higher levels of total cytokines were observed in HACM than in HAM. Epidermal growth factor (EGF) level was significantly higher in d-HAM than in the other samples. The levels of most of the other growth factors were higher in HACM than in HAM, but there was no statistical difference between the dehydration process and the fresh-freezing process. The levels of the cytokines, other than the growth factors, were higher in HACM than in HAM, and higher concentrations of cytokines were observed in the freezing group than in the dehydration group. Histological examination revealed that the dehydration group had thinner tissues than the freezing group, but the structural stability, including the basement membrane, did not differ between the two groups. Microscopic structures such as microvilli and nuclei were well-preserved in the freezing group, based on the results of the transmission electron microscopy. Our dehydration process maintained the histological structure of HAM/HACM and a variety of growth factors and cytokines were identified. Especially, the HAM, processed with the dehydration method, had a higher EGF level than that processed with the fresh-freezing method. Therefore, dehydration method can be used to effectively promote wound repair.

Skeletal muscle as a protagonist in the pregnancy metabolic syndrome

The pregnant woman normally shows clinical manifestations similar to a metabolic syndrome (MS), due to her metabolic and hemodynamic adaptations in order to share nutrients with the child. If those adjustments are surpassed, a kind of pregnancy MS (PregMS) could appear, characterized by excessive insulin resistance and vascular maladaptation. Skeletal muscle (SKM) must be a protagonist in the PregMS: SKM strength and mass have been associated inversely with MS incidence in non-pregnant patients, and in pregnant women muscular activity modulates metabolic and vascular adaptations that favor better outcomes. Of note, a sedentary lifestyle affects exactly in the other way. Those effects may be explained not only by the old paradigm of SKM being a great energy consumer and store, but because it is an endocrine organ whose chronic activity or deconditioning correspondingly releases myokines modulating insulin sensitivity and cardiovascular adaptation, by direct or indirect mechanisms not well understood. In this document, we present evidence to support the concept of a PregMS and hypothesize on the role of the SKM mass, fiber types composition and myokines in its pathophysiology. Also, we discuss some exercise interventions in pregnancy as a way to test our hypotheses.

Expression of Placenta Growth Factor Is Associated with Unfavorable Prognosis of Advanced-Stage Serous Ovarian Cancer

Ovarian cancer is the fourth leading cause of cancer death in women and the most fatal gynecologic malignancy. Placenta growth factor (PGF), a member of the vascular endothelial growth factor, plays an important role in angiogenesis. The overexpression of PGF was observed in several types of cancers, but the clinical significance of PGF in epithelial ovarian cancer (EOC) is still unknown. To explore the prognostic value of PGF among patients with serous EOC, we analyzed the expression of PGF in 89 EOC specimens by immunohistochemistry. The scoring system of immunohistochemistry was based on the staining intensity and the percentage of PGF-positive cells in each EOC tissue. According to the immunohistochemical score, 34 patients with score ≥ 6 were defined as high PGF expression, and other 55 patients were the group with low PGF expression. The prognostic significance of PGF expression was analyzed. EOC patients with higher IHC scores of PGF expression are significantly associated with positive lymphatic invasion and poorer response to chemotherapy. Patients with higher IHC scores of PGF expression had poorer response to chemotherapy and lower overall survival rate. Additionally, the positive lymph node metastasis, advanced TNM stage, and poorer response to chemotherapy were all remarkably correlated to poorer prognosis. In conclusion, patients with higher PGF in EOC tissues were more predisposed to positive lymphatic invasion, poorer response to chemotherapy and unfavorable prognosis of patients with serous EOC. We propose that PGF expression may be predictive of chemoresistance and poor prognosis of serous EOC.

The plasma level changes of VEGF and soluble VEGF receptor-1 are associated with high-altitude pulmonary edema

Hypoxia-induced plasma levels of VEGF and sFlt-1 are responsible for increased vascular permeability occurred in both brain and pulmonary edema. Currently, it remains unclear the exact roles of VEGF and sFlt-1 in High Altitude Pulmonary Edema (HAPE) pathogenesis. In this study, plasma levels of VEGF and sFlt-1 from 10 HAPE and 10 non-HAPE subjects were measured and compared. The results showed that plasma levels of both VEGF and sFlt-1 in HAPE patients were significantly increased as compared to the non-HAPE group. Interestingly, increased plasma levels of these two protein factors were markedly reduced after treatments. As compared to VEGF, sFlt-1 was much more affected by hypoxia and treatments, suggesting this factor was a key factor contributed to HAPE pathogenesis. Importantly, the ratio of sFlt-1 and VEGF in group of either non-HAPE or HAPE after recovery was significantly lower than the ratio in HAPE patients prior to treatments. Our findings suggested that sFlt-1 was a key factor that involved in HAPE pathogenesis and the sFlt-1/VEGF ratio could be used as a sensitive diagnostic marker for HAPE. J. Med. Invest. 65:64-68, February, 2018.

Analysis of Methyldopa Therapy on sFlt-1 Antiangiogenic Levels in Patients with Severe Preeclampsia

Methyldopa is the first-line drugs to treat hypertension in pregnancy. It can decrease blood pressure in preeclampsia by affecting a2-adrenoreceptors in central nervous system. However, it could also act by decreasing  production of sFlt-1 antiangiogenic protein levels involved in the pathophysiology of hypertention  in preeclampsia. The purpose of this study was to analyze methyldopa therapy on sFlt-1 antiangiogenic levels in the plasma of pregnant women with severe preeclampsia at the Obstetric Departement, Haji Hospital, Surabaya. This was a prospective study with observational cross-section study design. The sFlt-1 angiogenic levels were observed before and after (48 hours) methyldopa administration in severe preeclampsia patient with or without complications in the period of August to October 2016. Patient received methyldopa 250 mg or 500 mg, three times a day for clinical indications according a standard protocol. The study was approved by the ethical committee of Haji Hospital, Surabaya. There were 19 patients with preeclampsia who met the inclusion criteria, showed a decrease in the levels of sFlt-1 before and 48 hours after methyldopa therapy. Levels of sFlt-1 before methyldopa therapy in a dose of 250 mg was 10.15±10.00 (2.55-34.70) ng/ml and after therapy 8,37±9,20 (0.72-9.20) ng/ml, with a percentage decrease 17.54%. sFlt-1 levels before methyldopa therapy in a dose of 500 mg was 8.05±7.07 (2.55-20.76) ng/ml, after  therapy 4.50±2.90 (2.19-9.95) ng/ml, with a percentage decrease 44.16%. Methyldopa therapy could decrease sFlt-1 levels of antiangiogenic factor in patients with severe preeclampsia.

Understanding biological mechanisms underlying adverse birth outcomes in developing countries: protocol for a prospective cohort (AMANHI bio-banking) study

Objectives

The AMANHI study aims to seek for biomarkers as predictors of important pregnancy–related outcomes, and establish a biobank in developing countries for future research as new methods and technologies become available.

Methods

AMANHI is using harmonised protocols to enrol 3000 women in early pregnancies (8–19 weeks of gestation) for population–based follow–up in pregnancy up to 42 days postpartum in Bangladesh, Pakistan and Tanzania, with collection taking place between August 2014 and June 2016. Urine pregnancy tests will be used to confirm reported or suspected pregnancies for screening ultrasound by trained sonographers to accurately date the pregnancy. Trained study field workers will collect very detailed phenotypic and epidemiological data from the pregnant woman and her family at scheduled home visits during pregnancy (enrolment, 24–28 weeks, 32–36 weeks & 38+ weeks) and postpartum (days 0–6 or 42–60). Trained phlebotomists will collect maternal and umbilical blood samples, centrifuge and obtain aliquots of serum, plasma and the buffy coat for storage. They will also measure HbA1C and collect a dried spot sample of whole blood. Maternal urine samples will also be collected and stored, alongside placenta, umbilical cord tissue and membrane samples, which will both be frozen and prepared for histology examination. Maternal and newborn stool (for microbiota) as well as paternal and newborn saliva samples (for DNA extraction) will also be collected. All samples will be stored at –80°C in the biobank in each of the three sites. These samples will be linked to numerous epidemiological and phenotypic data with unique study identification numbers.

Importance of the study

AMANHI biobank proves that biobanking is feasible to implement in LMICs, but recognises that biobank creation is only the first step in addressing current global challenges.

Antihypertensive methyldopa, labetalol, hydralazine, and clonidine reversed tumour necrosis factor-α inhibited endothelial nitric oxide synthase expression in endothelial-trophoblast cellular networks

Medications used to control hypertension in pregnancy also improve trophoblast and endothelial cellular interaction in vitro. Tumour necrosis factor-α (TNF-α) inhibits trophoblast and endothelial cellular interactions and simultaneously decreases endothelial nitric oxide synthase (eNOS) expression. This study investigated whether antihypertensive medications improved these cellular interactions by modulating eNOS and inducible nitric oxide synthase (iNOS) expression. Human uterine myometrial microvascular endothelial cells (UtMVECs) were pre-incubated with (or without) low dose TNF-α (0.5 ng/mL) or TNF-α plus soluble fms-like tyrosine kinase-1 (sFlt-1) (100 ng/mL). The endothelial cells were cultured on Matrigel. After endothelial cellular networks appeared, trophoblast derived HTR-8/SVneo cells were co-cultured in the presence of clinically relevant doses of methyldopa, labetalol, hydralazine or clonidine for 24 hours. Cells were retrieved from the Matrigel to extract mRNA and eNOS and iNOS expression were examined by quantitative PCR. Methyldopa, labetalol, hydralazine and clonidine reversed the inhibitory effect of TNF-α on eNOS mRNA expression. After pre-incubating endothelial cells with TNF-α and sFlt-1, all the medications except methyldopa lost their effect on eNOS mRNA expression. In the absence of TNF-α, antihypertensive medications did not change eNOS expression. The mRNA expression of iNOS was not affected by TNF-α or any medications. This study shows that selected antihypertensive medications used in the treatment of hypertension in pregnancy increase eNOS expression in vitro when induced by the inflammatory TNF-α. The anti-angiogenic molecule sFlt-1 may antagonise the potential benefit of these medications by interfering with the NOS pathway.

Evaluation of agreement of placental growth factor (PlGF) tests and the soluble FMS-like tyrosine kinase 1 (sFlt-1)/PlGF ratio, comparison of predictive accuracy for pre-eclampsia, and relation to uterine artery Doppler and response to aspirin

OBJECTIVES

The objective of this study is to evaluate agreement between PlGF and sFlt-1/PlGF ratio tests and compare their predictive accuracy for pre-eclampsia in high-risk women. Also, to examine for associations of abnormal PlGF or sFlt-1/PlGF ratio with abnormal uterine artery Doppler and platelet response to aspirin.

METHODS

Prospective cohort study, 150 pregnant women at high risk of pre-eclampsia prescribed 75 mg aspirin daily. Uterine artery Dopplers were assessed at 20⁺⁰-23⁺⁶ weeks. At 33⁺⁰-35⁺⁶ weeks platelet function aspirin metabolites, PlGF and the sFlt-1/PlGF ratio were measured.

OUTCOME

Measures were all pre-eclampsia and pre-eclampsia requiring delivery prior to 37 weeks.

RESULTS

Overall percent agreement was 89.3% for PlGF tests but 74.7-78% for PlGF tests and the sFlt-1/PlGF ratio. AUCs were 0.70-0.75 for prediction of any pre-eclampsia and 0.92-0.99 for preterm pre-eclampsia. We found a significant association between abnormal PlGF or sFlt-1/PlGF ratio and abnormal uterine artery Doppler (χ² 5.47, p = .019), but no association with platelet response to aspirin (χ² 0.12, p = .913). There were no associations between suboptimal aspirin adherence and either abnormal angiogenic markers or uterine artery Dopplers (χ² 0.144, 0.038, p = .704, .846, respectively).

CONCLUSIONS

There was good agreement between PlGF tests and limited agreement between PlGF tests and the sFlt-1/PlGF ratio. All tests have heightened predictive accuracy for preterm pre-eclampsia. Abnormal PlGF or sFlt-1/PlGF ratio relates to abnormal uterine artery Doppler but not platelet response to aspirin.

Low Soluble Fms-Like Tyrosine Kinase-1, Endoglin, and Endothelin-1 Levels in Women With Confirmed or Suspected Preeclampsia Using Proton Pump Inhibitors

Patients with preeclampsia display elevated placenta-derived sFlt-1 (soluble Fms-like tyrosine kinase-1) and endoglin levels and decreased placental growth factor levels. Proton pump inhibitors (PPIs) decrease trophoblast sFlt-1 and endoglin secretion in vitro. PPIs are used during pregnancy to combat reflux disease. Here, we investigated whether PPIs affect sFlt-1 in women with confirmed/suspected preeclampsia, making use of a prospective cohort study involving 430 women. Of these women, 40 took PPIs (6 esomeprazole, 32 omeprazole, and 2 pantoprazole) for 8 to 45 (median 29) days before sFlt-1 measurement. Measurements were only made once, at study entry between weeks 20 and 41 (median 33 weeks). PPI use was associated with lower sFlt-1 levels, with no change in placental growth factor levels, both when compared with all non-PPI users and with 80 gestational age-matched controls selected from the non-PPI users. No sFlt-1/placental growth factor alterations were observed in women using ferrous fumarate or macrogol while, as expected, women using antihypertensive medication displayed higher sFlt-1 levels and lower placental growth factor levels. The PPI use-associated decrease in sFlt-1 was independent of the application of antihypertensive drugs and also occurred when restricting our analysis to patients with hypertensive disease of pregnancy at study entry. PPI users displayed more cases with preexisting proteinuria, less gestational hypertension, and a lower number of neonatal sepsis cases. Finally, their plasma endoglin and endothelin-1 levels were lower while sFlt-1 levels correlated positively with both. In conclusion, PPI use associates with low sFlt-1, endoglin, and endothelin-1 levels, warranting prospective trials to investigate the therapeutic potential of PPIs in preeclampsia.

Embryotoxicity Caused by DON-Induced Oxidative Stress Mediated by Nrf2/HO-1 Pathway

Deoxynivalenol (DON) belongs to the type B group of trichothecenes family, which is composed of sesquiterpenoid metabolites produced by Fusarium and other fungi in grain. DON may cause various toxicities, such as cytotoxicity, immunotoxicity, genotoxicity as well as teratogenicity and carcinogenicity. In the present study, we focus on a hypothesis that DON alters the expressions of Nrf2/HO-1 pathway by inducing embryotoxicity in C57BL/6 mouse (5.0, 2.5, 1.0, and 0 mg/kg/day) and BeWo cell lines (0 and 50 nM; 3 h, 12 h and 24 h). Our results indicate that DON treatment in mice during pregnancy leads to ROS accumulation in the placenta, which results in embryotoxicity. At the same time Nrf2/HO-1 pathway is up-regulated by ROS to protect placenta cells from oxidative damage. In DON-treated BeWo cells, the level of ROS has time–effect and dose–effect relationships with HO-1 expression. Moderate increase in HO-1 protects the cell from oxidative damage, while excessive increase in HO-1 aggravates the oxidative damage, which is called in some studies the “threshold effect”. Therefore, oxidative stress may be the critical molecular mechanism for DON-induced embryotoxicity. Besides, Nrf2/HO-1 pathway accompanied by the “threshold effect” also plays an important role against DON-induced oxidative damage in this process.

Angiogenesis in the placenta: the role of reactive oxygen species signaling

Proper placental development and function are central to the health of both the mother and the fetus during pregnancy. A critical component of healthy placental function is the proper development of its vascular network. Poor vascularization of the placenta can lead to fetal growth restriction, preeclampsia, and in some cases fetal death. Therefore, understanding the mechanisms by which uterine stressors influence the development of the placental vasculature and contribute to placental dysfunction is of central importance to ensuring a healthy pregnancy. In this review we discuss how oxidative stress observed in maternal smoking, maternal obesity, and preeclampsia has been associated with aberrant angiogenesis and placental dysfunction resulting in adverse pregnancy outcomes. We also highlight that oxidative stress can influence the expression of a number of transcription factors important in mediating angiogenesis. Therefore, understanding how oxidative stress affects redox-sensitive transcription factors within the placenta may elucidate potential therapeutic targets for correcting abnormal placental angiogenesis and function.

In-vitro study of the effect of anti-hypertensive drugs on placental hormones and angiogenic proteins synthesis in pre-eclampsia

INTRODUCTION

Antihypertensive drugs lower the maternal blood pressure in pre-eclampsia (PE) by direct or central vasodilatory mechanisms but little is known about the direct effects of these drugs on placental functions.

OBJECTIVE

The aim of our study is to evaluate the effect of labetolol, hydralazine, α-methyldopa and pravastatin on the synthesis of placental hormonal and angiogenic proteins know to be altered in PE.

DESIGN

Placental villous explants from late onset PE (n = 3) and normotensive controls (n = 6) were cultured for 3 days at 10 and 20% oxygen (O2) with variable doses anti-hypertensive drugs. The levels of activin A, inhibin A, human Chorionic Gonadotrophin (hCG), soluble fms-like tyrosine kinase-1 (sFlt-1) and soluble endoglin (sEng) were measured in explant culture media on day 1, 2 and 3 using standard immunoassays. Data at day 1 and day 3 were compared.

RESULTS

Spontaneous secretion of sEndoglin and sFlt-1 were higher (p < 0.05) in villous explants from PE pregnancies compared to controls. There was a significant time dependent decrease in the secretion of sFlt-1 and sEndoglin in PE cases, which was seen only for sFlt-1 in controls. In both PE cases and controls the placental protein secretions were not affected by varying doses of anti-hypertensive drugs or the different O2 concentration cultures, except for Activin, A which was significantly (p < 0.05) higher in controls at 10% O2.

INTERPRETATION

Our findings suggest that the changes previously observed in maternal serum hormones and angiogenic proteins level after anti-hypertensive treatment in PE could be due to a systemic effect of the drugs on maternal blood pressure and circulation rather than a direct effect of these drugs on placental biosynthesis and/or secretion.

Gestational loss and growth restriction by angiogenic defects in placental growth factor transgenic mice

OBJECTIVE

Angiogenesis is an important biological process during development, reproduction, and in immune responses. Placental growth factor (PlGF) is a member of vascular endothelial growth factor that is critical for angiogenesis and vasculogenesis. We generated transgenic mice overexpressing PlGF in specifically T cells using the human CD2-promoter to investigate the effects of PlGF overexpression.

APPROACH AND RESULTS

Transgenic mice were difficult to obtain owing to high lethality; for this reason, we investigated why gestational loss occurred in these transgenic mice. Here, we report that placenta detachment and inhibition of angiogenesis occurred in PlGF transgenic mice during the gestational period. Moreover, even when transgenic mice were born, their growth was restricted.

CONCLUSIONS

Conclusively, PlGF overexpression prevents angiogenesis by inhibiting Braf, extracellular signal-regulated kinase activation, and downregulation of HIF-1α in the mouse placenta. Furthermore, it affected regulatory T cells, which are important for maintenance of pregnancy.

Maternal and fetoplacental hypoxia do not alter circulating angiogenic growth effectors during human pregnancy

One causal model of preeclampsia (PE) postulates that placental hypoxia alters the production of angiogenic growth effectors (AGEs), causing an imbalance leading to maternal endothelial cell dysfunction. We tested this model using the natural experiment of high-altitude (HA) residence. We hypothesized that in HA pregnancies 1) circulating soluble fms-like tyrosine kinase 1 (sFlt-1) is increased and placental growth factor (PlGF) decreased, and 2) AGE concentrations correlate with measures of hypoxia. A cross-sectional study of healthy pregnancies at low altitude (LA) (400 m) versus HA (3600 m) compared normal (n = 80 at HA, n = 90 at LA) and PE pregnancies (n = 20 PE at HA, n = 19 PE at LA). Blood was collected using standard serum separation and, in parallel, by a method designed to inhibit platelet activation. AGEs were measured by enzyme-linked immunosorbent assays. AGEs did not differ between altitudes in normal or PE pregnancies. AGE concentrations were unrelated to measures of maternal or fetal hypoxia. PlGF was lower and sFlt-1 higher in PE, but overlapped considerably with the range observed in normal samples. PlGF correlated with placental mass in both normal and PE pregnancies. The contribution of peripheral cells to the values measured for AGEs was similar at LA and HA, but was greater in PE than in normotensive women. Hypoxia, across a wide physiological range in pregnancy, does not alter levels of circulating AGEs in otherwise normal pregnancies. Peripheral cell release of AGEs with the hemostasis characteristic of standard blood collection is highly variable and contributes to a doubling of the amount of sFlt-1 measured in PE as compared to normal pregnancies.

Comparison of placental growth factor and fetal flow Doppler ultrasonography to identify fetal adverse outcomes in women with hypertensive disorders of pregnancy: an observational study

BACKGROUND

Hypertensive disorders of pregnancy and intrauterine growth restriction (IUGR) are leading causes of maternal and perinatal morbidity and mortality. Failure to detect intrauterine growth restriction in women at high risk has been highlighted as a significant avoidable cause of serious fetal outcome. In this observational study we compare fetal flow using Doppler ultrasonography with a new test for placental growth factor (PlGF) to predict fetal adverse events.

METHODS

Eighty-nine women with hypertensive disorders of pregnancy (24 with chronic hypertension, 17 with gestational hypertension, 12 with HELLP syndrome, 19 with preeclampsia and 17 with superimposed preeclampsia) were enrolled. A single maternal blood sample to measure free PlGF (Alere Triage) taken before 35 weeks of pregnancy was compared to the last Doppler ultrasound measurement of fetal flow before delivery. PlGF was classified as normal (PlGF≥100 pg/ml), low (12<PlGF<100) or very low (PlGF≤12 pg/ml). A positive test for abnormal fetal flow was defined as either signs of centralisation of the fetal circulation or diastolic block or reverse flow in the umbilical artery or descending aorta; this was a criterion for delivery. Fetal outcomes were intrauterine growth restriction and birth before 37 weeks of pregnancy.

RESULTS

In total 61/89 women had a preterm birth and 22 infants had IUGR. Of those who delivered preterm, 20/20 women with abnormal fetal flow and 36/41 (87.8%) women with normal fetal flow had low or very low PlGF. Of those infants with IUGR, 22/22 had low or very low maternal PlGF and 10/22 had abnormal fetal flow.

CONCLUSIONS

PlGF may provide useful information before 35th gestational week to identify fetuses requiring urgent delivery, and those at risk of later adverse outcomes not identified by fetal flow Doppler ultrasonography.

Growth factors in preeclampsia: a vascular disease model. A failed vasodilation and angiogenic challenge from pregnancy onwards?

Preeclampsia is the major cause of maternofetal and neonatal morbi-mortality including intrauterine growth retardation, miscarriages and stillbirths. Inadequate vascular dilation and angiogenesis represent the crucial underlying defect of gravidic hypertension, denoting a failed response to the vasodilatory and pro-angiogenic challenge imposed by pregnancy, especially if multifetal. A similar pathogenesis appears involved in gestational diabetes. In this review we aimed to provide a hint on understanding the deeply involved angiogenic disorders which eventually culminate in utero-placental failure. The key players in these complex processes may be found in an intricate network of growth factors (GFs) and GF inhibitors, controlled by several vascular risk factors modulated by environment and genes, which eventually impact on early and late cardiovascular outcomes of mother and fetus.

Placental growth factor (PlGF): a key to optimizing fetal growth

The needs of the uterus and the fetus for the provision of nutrients and oxygen, supplied by the blood flow, are understandably extremely high, with the circulatory system playing the most important role in this action. Abnormal vascular growth and transformation that create a high vessel resistance network have been associated with various pregnancy pathologies, including miscarriage, small for gestational age (SGA) fetuses with or without preeclampsia and intrauterine growth restriction (IUGR). Placental growth factor (PlGF) has a major role in vasculogenesis and angiogenesis in human placenta. Low concentrations of PlGF and high concentrations of its inhibitor-soluble Fms-like tyrosine kinase-1 (sFlt-1) are linked with impaired angiogenesis and placental development, leading to the above pregnancy complications. The activity of vascular endothelial growth factor (VEGF), which is the most potent of all angiogenic mediators, is partly modulated by PlGF. Although the mechanisms via which PlGF exerts its various effects are still under investigation, we herein discuss the known actions exerted by this major mediator together with its results on fetal growth.

Evaluation of a rapid and simple placental growth factor test in hypertensive disorders of pregnancy

The aim of this study was to investigate the diagnostic accuracy of the Triage placental growth factor (PlGF) assay, together with its prognostic efficiency in determining the need for preterm delivery in all forms of hypertensive disorders of pregnancy. A total of 130 pregnant women with a diagnosis of preeclampsia (PE: 23), HELLP syndrome (20), superimposed preeclampsia (SIPE: 17), chronic hypertension (CHT: 25), gestational hypertension (GHT: 18) and 27 normotensive pregnant controls were enrolled in this case-control study. A single blood sample was taken between 22 and 34 weeks of gestation, and the plasma was analyzed for PlGF using the Alere Triage PlGF assay. The PlGF levels found in all hypertensive disorder groups differed significantly from those observed in controls. There was a highly significant difference in PlGF concentrations between women with a pregnancy duration <35 weeks and controls. Using a gestational age-dependent threshold of 5% of normal, a positive PlGF test predicted delivery before 35 weeks in 93.7% of hypertensive women and delivery before 37 weeks in 90.5% of hypertensive women. A positive PlGF test identified the following proportions of hypertensive patients: 95.7% (PE), 95.0% (HELLP syndrome), 82.4% (SIPE), 60.0% (CHT) and 44.4% (GHT). A positive PlGF test was associated with a significantly shorter duration of pregnancy (hazard ratio of 3.43 adjusted for the gestational age at the time of sample collection and hypertension with proteinuria). In conclusion, PlGF concentrations are significantly lower in all hypertensive disorders. A positive test using the Triage PlGF assay at 22-34 weeks of gestation predicts delivery before 37 weeks in women with both proteinuric and non-proteinuric hypertensive disorders of pregnancy.

Comparison of angiogenic and anti-angiogenic factors in maternal and umbilical cord blood in early- and late-onset pre-eclampsia

PURPOSE

The aim of this study was to compare maternal and umbilical cord serum levels of the angiogenic and anti-angiogenic factors in early- and late-onset pre-eclamptic pregnancies as well as in normal pregnancies, which might have significant importance in the etiology of pre-eclampsia.

MATERIALS AND METHODS

This prospective case-control study was carried out with pre-eclamptic (early-onset, ≤ 34 weeks and late-onset, >34 weeks) and normal pregnant women. VEGF, PIGF, sFlt-1 and sEng levels in maternal and umbilical cord serum were measured before delivery and the findings were compared.

RESULTS

The study was conducted with 15 early- and 15 late-onset pre-eclampsia patients, and 17 patients with normal pregnancies. It was found that sEng levels were higher in the umbilical cord serum in the early-onset and in the maternal serum in the late-onset pre-eclampsia group than the control group (p < 0.05). No significant difference in any factor was observed between the early- and late-onset pre-eclampsia groups.

CONCLUSION

In this study, the results showed that angiogenic and anti-angiogenic factor levels in maternal serum and umbilical cord serum may not be related to the time of onset of pre-eclampsia.

Endothelial growth factor therapy improves preeclampsia-like manifestations in a murine model induced by overexpression of sVEGFR-1

This study examines the effects of VEGF-121 therapy in an animal model of preeclampsia induced by overexpression of soluble VEGF receptor 1 (sVEGFR-1). At day 8 of gestation, CD-1 mice were implanted with subcutaneous osmotic pumps containing either VEGF-121 or vehicle and fitted with telemetric blood pressure (BP) catheters for continuous BP monitoring ( days 8–18 of gestation). On day 9, the animals in the VEGF-121 group were randomly allocated for injection with adenovirus carrying sVEGFR-1 or the murine immunoglobulin G2α Fc fragment (mFc) as virus control (Adv-sVEGFR-1; Adv-mFc). Animals in the vehicle group were injected with Adv-sVEGFR-1. On day 18, mice were euthanized, placentas and pups weighted, carotid arteries isolated, and their responses studied in vitro using a wire myograph for isometric tension recording. In mice overexpressing sVEGFR-1, treatment with VEGF-121 significantly reduced BP from days 10 to 18 of gestation compared with that of vehicle. VEGF-sVEGFR-1 animals had significantly higher vasorelaxant response to sodium nitroprusside and significantly lower contractile response to the thromboxane agonist (U-46619) compared with that of the vehicle-sVEGFR-1 mice. Phenylephrine and acetylcholine responses did not significantly vary between the VEGF-sVEGFR-1 and the vehicle-sVEGFR-1 mice. Average pup weight was significantly lower in the vehicle-sVEGFR-1 group compared with the VEGF-sVEGFR-1 and VEGF-mFc groups. In conclusion, VEGF-121 therapy attenuates vascular dysfunction and diminishes intrauterine growth abnormality in an animal model of preeclampsia induced by overexpression of sVEGFR-1. Modulation of VEGF pathway turns into a promising therapeutic approach of preeclampsia.

Nitric oxide generation affects pro- and anti-angiogenic growth factor expression in primary human trophoblast

OBJECTIVES

Preeclampsia is associated with reduced trophoblast placenta growth factor (PGF) expression, elevated soluble fms-like tyrosine kinase-1 (sFlt-1) and decreased bioactivity of nitric oxide (NO). Elevated sFlt-1 reduces bio-availability of PGF and vascular endothelial growth factor (VEGF) leading to maternal endothelial dysfunction. Although NO can regulate gene expression, its ability to regulate trophoblast expression of angiogenic growth factors is not known.

STUDY DESIGN

Human primary term trophoblast and JEG-3 choriocarcinoma cells were cultured under 21%O(2) or 1%O(2) conditions in the presence or absence of NO donor (SNP) or inhibitor (L-NAME). Effects on PGF, VEGF and Flt-1 isoform mRNA expression were determined by quantitative real-time PCR. Changes in expression of soluble protein isoforms of FLT-1 was monitored by ELISA.

RESULTS

Hypoxia decreased PGF mRNA but increased VEGF, sFlt-1 and Flt-1 mRNA expression in trophoblast. Generation of NO in trophoblast under 1%O(2) culture conditions significantly reversed sFlt-1 mRNA and protein expression, independent of mFlt-1. Conversely NO generation in hypoxic trophoblast increased VEGF and PGF mRNA expression.

CONCLUSIONS

NO production in primary human trophoblast cultures had divergent effects on pro-angiogenic (PGF, VEGF) versus anti-angiogenic (sFlt-1) mRNA expression, resulting in an enhanced pro-angiogenic gene expression environment in vitro.

Bothrops jararaca peptide with anti-hypertensive action normalizes endothelium dysfunction involved in physiopathology of preeclampsia

Preeclampsia, a pregnancy-specific syndrome characterized by hypertension, proteinuria and edema, is a major cause of fetal and maternal morbidity and mortality especially in developing countries. Bj-PRO-10c, a proline-rich peptide isolated from Bothrops jararaca venom, has been attributed with potent anti-hypertensive effects. Recently, we have shown that Bj-PRO-10c-induced anti-hypertensive actions involved NO production in spontaneous hypertensive rats. Using in vitro studies we now show that Bj-PRO-10c was able to increase NO production in human umbilical vein endothelial cells from hypertensive pregnant women (HUVEC-PE) to levels observed in HUVEC of normotensive women. Moreover, in the presence of the peptide, eNOS expression as well as argininosuccinate synthase activity, the key rate-limiting enzyme of the citrulline-NO cycle, were enhanced. In addition, excessive superoxide production due to NO deficiency, one of the major deleterious effects of the disease, was inhibited by Bj-PRO-10c. Bj-PRO-10c induced intracellular calcium fluxes in both, HUVEC-PE and HUVEC, which, however, led to activation of eNOS expression only in HUVEC-PE. Since Bj-PRO-10c promoted biological effects in HUVEC from patients suffering from the disorder and not in normotensive pregnant women, we hypothesize that Bj-PRO-10c induces its anti-hypertensive effect in mothers with preeclampsia. Such properties may initiate the development of novel therapeutics for treating preeclampsia.

Periodic assessment of plasma sFlt-1 and PlGF concentrations and its association with placental morphometry in gestational hypertension (GH) - a prospective follow-up study

BACKGROUND

Hypertensive disorders in pregnancy contributes to about 12% of maternal deaths in Malaysia and similarly worldwide. Early detection and adequate management are preventable strategies. Biochemical markers of abnormal angiogenesis would be more specific in early detection than routine blood pressure and proteinuria measurements. The aim of this study was to estimate maternal plasma PlGF and sFlt-1 levels in pregnant women with gestational hypertension at three intervals of pregnancy and correlate these biomarker levels with placental morphometry.

METHODS

Venous blood samples (antepartum, intrapartum and post partum periods) were drawn to estimate for sFlt-1 and PlGF levels while placental tissue samples were examined for placental morphometry.

RESULTS

PlGF levels were lower in gestational hypertension (GH) compared to normotensive during antepartum and intrapartum period, whereas sFlt-1 levels were elevated in GH at antepartum, intrapartum and postpartum intervals during pregnancy. An inverse relationship between these two biomarkers was observed through correlation analysis. PlGF levels were inversely correlated with total villous surface area of the placental periphery (TCsa-C) and villous capillarization (VC-C) of the placental periphery.

CONCLUSION

We established periodic values of for sFlt-1 and PlGF levels for the first time in an ethnically diverse Malaysian setting. We suggest the development of GH in women is related to defective capillarization. In demonstrating periodic changes, this study suggest the possibility of developing GH and other long term health complications as a result of prolonged exposure to sFlt-1. The correlation between PlGF levels and morphometric findings also support possible capillarization defect.

Effect of antihypertensive therapy with alpha-methyldopa on uterine artery Doppler in pregnancies with hypertensive disorders

OBJECTIVES

Antihypertensive drugs lower blood pressure by direct vascular effects or central vasodilatory mechanisms. Their effect on uterine artery Doppler resistance indices in hypertensive disorders of pregnancy is uncertain. This study aimed to evaluate the impact of antihypertensive therapy with alpha-methyldopa on maternal uterine artery Doppler pulsatility index (PI) and resistance index (RI) in women presenting with hypertensive disorders of pregnancy.

METHODS

This was a cross-sectional study of 51 women with pre-eclampsia, 29 with gestational hypertension and 80 matched normotensive controls. Uterine artery PI and RI were measured at recruitment (between 24 and 40 weeks' gestation) and, in the hypertensive groups, 24-48 h after starting alpha-methyldopa. Differences between mild and severe, and between early- and late-onset pre-eclampsia were compared using the Mann-Whitney test. The Wilcoxon rank sum test was used to compare measurements before and after treatment.

RESULTS

Prior to treatment, uterine artery PI and RI were significantly higher in women with pre-eclampsia compared with those with gestational hypertension and controls (P < 0.0001). The median uterine artery PI multiple of the median (MoM) was significantly higher (P < 0.0001) in early-onset than in late-onset pre-eclampsia (1.83 (range, 0.88-3.65) vs. 1.19 (range, 0.91-1.72)) and in severe compared with mild disease (2.26 (range, 2.02-3.65) vs. 1.29 (range, 0.88-2.9)). Uterine artery PI- and RI-MoMs in both pre-eclampsia and gestational hypertension, before and after 34 weeks' gestation, were not affected by alpha-methyldopa treatment.

CONCLUSIONS

Antihypertensive therapy using alpha-methyldopa in women presenting with hypertensive disorders of pregnancy has no significant effect on uterine artery resistance to blood flow, suggesting that it does not impair uteroplacental circulation in these cases.

The role of urinary soluble endoglin in the diagnosis of pre-eclampsia: comparison with soluble fms-like tyrosine kinase 1 to placental growth factor ratio

OBJECTIVE

Endoglin, an anti-angiogenic glycoprotein expressed on endothelial cells, has been proposed recently as a biomarker of pre-eclampsia (PE). Given that PE is characterised by an imbalance of angiogenic factors, we sought to determine the clinical utility of urinary soluble endoglin, relative to the soluble fms-like tyrosine kinase 1 to placental growth factor (PlGF) ratio, in the diagnosis of PE during gestation.

DESIGN

Prospective observational cohort.

SETTING

Tertiary referral university hospital.

POPULATION

Two hundred and thirty-four pregnant women were enrolled prospectively in the following groups: healthy controls, n = 63; gestational age (GA), median (interquartile range), 33 weeks (27-39 weeks); chronic hypertension, n = 27; GA, 33 weeks (30-36 weeks); mild PE, n = 38; GA, 37 weeks (34-40 weeks); severe PE, n = 106; GA, 32 weeks (29-37 weeks).

METHODS

Free urinary levels of soluble endoglin, soluble fms-like tyrosine kinase 1 and PlGF were measured by sensitive and specific immunoassay. Levels for all urinary analytes were normalised to creatinine.

MAIN OUTCOME MEASURES

Urinary soluble endoglin, and the soluble fms-like tyrosine kinase 1 to PlGF ratio.

RESULTS

In healthy controls, urinary soluble endoglin levels were increased significantly at term relative to those earlier in gestation. Severe PE was characterised by an increased urinary level of soluble endoglin, soluble fms-like tyrosine kinase 1, protein to creatinine ratio and soluble fms-like tyrosine kinase 1 to PlGF ratio compared with all other groups. There was a direct correlation between urinary soluble endoglin and proteinuria that remained after GA correction (R = 0.382, P < 0.001). Urinary soluble endoglin could not differentiate mild PE from severe preterm PE. Overall, soluble endoglin had the ability to discriminate PE from chronic hypertension and healthy controls only in women who were evaluated at <37 weeks of GA. The sensitivity, specificity and accuracy of urinary soluble endoglin alone in the diagnosis of PE or in the identification of women with PE requiring a mandated delivery before 37 weeks of gestation were 70%, 86% and 76%, respectively. These values were inferior to those of the soluble fms-like tyrosine kinase 1 to PlGF ratio (P < 0.001). The addition of urinary soluble endoglin did not improve the diagnostic accuracy of the soluble fms-like tyrosine kinase 1 to PlGF ratio alone.

CONCLUSIONS

We have provided evidence that soluble endoglin is present and elevated in the urine of women who develop preterm PE. Urinary soluble endoglin has only limited ability to determine the severity of PE and to distinguish between PE and chronic hypertension both preterm and at term. Compared with urinary soluble endoglin, the soluble fms-like tyrosine kinase 1 to PlGF ratio remains a better marker of disease presence, severity and outcome.

Antihypertensive therapy and central hemodynamics in women with hypertensive disorders in pregnancy

OBJECTIVE

To estimate the changes in central hemodynamics features of pregnant women presenting with hypertensive disorders and to analyze the effects of standard antihypertensive treatment on maternal central hemodynamics.

METHODS

Applanation tonometry was used to record the radial artery pulse waveform in 80 women presenting with preeclampsia or gestational hypertension and 80 normotensive controls matched for gestational age. In each case, an averaged aortic waveform was derived and analyzed to calculate augmentation pressure and augmentation index at heart rate 75 beats per minute (bpm).

RESULTS

In women with preeclampsia and gestational hypertension, both augmentation pressure (P<.001 and P<.05, respectively) and augmentation index at heart rate 75 bpm (P<.001 and P<.001, respectively) were significantly higher than in controls. Augmentation pressure and augmentation index at heart rate 75 bpm were significantly higher in early- compared with late-onset preeclampsia (P<.001) and in severe compared with mild preeclampsia (P<.001). Antihypertensive therapy with alpha methyldopa resulted in a significant fall in both augmentation pressure and augmentation index at heart rate 75 bpm in preeclampsia (P<.001) but not in gestational hypertension.

CONCLUSION

Arterial stiffness is increased in women with hypertensive disorders of pregnancy compared with normotensive controls. In preeclampsia, vascular stiffness was significantly improved by antihypertensive treatment with alpha methyldopa, but remained higher than in normotensive controls.

Effects of anti-hypertensive drugs on production of soluble fms-like tyrosine kinase 1 and soluble endoglin from human normal and pre-eclamptic placentas in vitro

1. Increases in soluble fms-like tyrosine kinase 1 (sFlt-1) and soluble endoglin (sEng) contribute to the pathogenesis of pre-eclampsia. Soluble Flt-1 binds to circulating free vascular endothelial growth factor and placenta growth factor and this is associated with endothelial dysfunction. Soluble endoglin, a transforming growth factor (TGF)-beta coreceptor, was reported to synergize with sFlt-1 to amplify endothelial dysfunction by inhibiting TGF-beta1-mediated vasorelaxation. 2. The aim of the present study was to examine whether the antihypertensive drugs clonidine (0.08-1.3 microg/mL), diazoxide (25-300 microg/mL), frusemide (60-1000 microg/mL) and hydralazine (6.3-100 microg/mL) have any effect on placental production of sFlt-1 and sEng in placentas from normal and pre-eclamptic pregnancies. 3. Explants were taken from non-laboured term placentas of normal pregnancy (n = 5) and women with pre-eclampsia (n = 5). Villous explants were cultured with increasing doses of antihypertensive drugs. Placental sFlt-1 and sEng production was examined using ELISA. 4. Baseline sFlt-1 production was higher in placentas from women with pre-eclampsia than from normal pregnancy (4.5 +/- 1.4 vs 3.2 +/- 0.6 ng/mg of total protein, respectively; P < 0.001), as was sEng production (9.0 +/- 2.3 vs 4.1 +/- 0.6 ng/mg of total protein, respectively; P < 0.001). With the exception of frusemide, none of the antihypertensive drugs tested had any effect on sFlt-1 and sEng production from placental explants of normal pregnancy and women with pre-eclampsia. Increasing frusemide concentrations were correlated with increased sEng production in normal pregnancy (P < 0.005). 5. In conclusion, placental sFlt-1 and sEng production was higher in pre-eclampsia and antihypertensive drugs had no effect on placental production of sFlt-1 and sEng in vitro.