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

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.

Comparison of the effects on maternal endothelial cell activation: an in vitro study of anti-hypertensive drugs clinically used in pre-eclampsia

Endothelial cell dysfunction in pregnancy, which can be induced by placental factors, is the fundamental component of the pathogenesis of pre-eclampsia. The dysfunctional vascular endothelium disrupts the balance of vasodilatory and vasoconstrictive factors, resulting in increasing blood pressure. There is currently no effective treatment for pre-eclampsia and effective control of hypertension may reduce neonatal morbidity and mortality by prolonging gestation, especially in cases of early onset disease. To date methyldopa, labetalol, nifedipine and metoprolol are recommended for controlling blood pressure in pre-eclampsia. All of these drugs have different mechanisms of action. In this in vitro study we investigated whether different types of anti-hypertensive drugs could have different effects on improving maternal endothelial cell dysfunction. Endothelial cells (HMEC-1) were exposed to phorbol-12-myristate-13-acetate (PMA) or pre-eclamptic sera or extracellular vesicles (EVs) derived from pre-eclamptic placentae, in the presence of each of the studied anti-hypertensive drugs (methyldopa, labetalol, nifedipine and metoprolol) or placebo for 24 h. Endothelial cell-surface adhesion molecule (ICAM-1) and monocyte adhesion were measured. The expression of cell-face ICAM-1 by HMEC-1 cells and THP-1 monocyte adherent to HMEC-1 that were exposed to three separate well-known activators of endothelial cells in the presence of four anti-hypertensive drugs was significantly reduced regardless of the dose. However, the effect on the reduction of ICAM-1 expression and monocyte adhesion was not significantly different between the four medications. Our data suggest that the beneficial effect on improving endothelial cell function by these commonly prescribed anti-hypertensive drugs is seemingly independent of the anti-hypertensive mechanisms of the medication.

Modelling preeclampsia: a comparative analysis of the common human trophoblast cell lines

Preeclampsia remains a challenge without an effective therapy. Evidence supports targetability of soluble fms‐like tyrosine kinase‐1 (sFlt‐1) and soluble endoglin (sEng), which are released excessively from the placenta under ischemic and hypoxic stresses. We compared four trophoblast cell lines, BeWo, Jar, Jeg‐3, and HTR‐8/SVneo, in order to identify a suitable model for drug screening. Cultured trophoblasts were exposed to 1% oxygen vs. normoxia for 24‐48 hr; human umbilical vein and aortic endothelial cells were included for comparison. Supernatant sFlt‐1 and sEng concentrations were measured by ELISA, and sFlt‐1 mRNA expression determined by RT‐PCR. Cellular responses to experimental therapeutics were explored. All four trophoblast lines secreted sEng, which did not increase by hypoxia. BeWo, Jar, and Jeg‐3 exhibited significantly enhanced expression of sFlt‐1 i13 and e15a mRNA in response to hypoxia; however, only BeWo released a detectable level of sFlt‐1 protein, which was doubled by hypoxia. In contrast, hypoxia decreased sFlt‐1 mRNA expression and protein release in HTR‐8/SVneo, similarly to endothelial cells. The cellular mechanism involved HIFα. BeWo responded to representative agents similarly to human primary placental tissues in the literature. These data support that the BeWo‐hypoxia model mimics a key pathogenic mechanism of preeclampsia and has potential value for translational drug discovery.

Developing novel in vitro methods for the risk assessment of developmental and placental toxicants in the environment

During pregnancy, the placenta is critical for the regulation of maternal homeostasis and fetal growth and development. Exposures to environmental chemicals during pregnancy can be detrimental to the health of the placenta and therefore adversely impact maternal and fetal health. Though research on placental-derived developmental toxicity is expanding, testing is limited by the resources required for traditional test methods based on whole animal experimentation. Alternative strategies utilizing in vitro methods are well suited to contribute to more efficient screening of chemical toxicity and identification of biological mechanisms underlying toxicity outcomes. This review aims to summarize methods that can be used to evaluate toxicity resulting from exposures during the prenatal period, with a focus on newer in vitro methods centered on placental toxicity. The following key aspects are reviewed: (i) traditional test methods based on animal developmental toxicity testing, (ii) in vitro methods using monocultures and explant models, as well as more recently developed methods, including co-cultures, placenta-on-a-chip, and 3-dimensional (3D) cell models, (iii) endpoints that are commonly measured using in vitro designs, and (iv) the translation of in vitro methods into chemical evaluations and risk assessment applications. We conclude that findings from in vitro placental models can contribute to the screening of potentially hazardous chemicals, elucidation of chemical mechanism of action, incorporation into adverse outcome pathways, estimation of doses eliciting toxicity, derivation of extrapolation factors, and characterization of overall risk of adverse outcomes, representing key components of chemical regulation in the 21^st century.

The performance of pre-delivery serum concentrations of angiogenic factors in predicting postpartum antihypertensive drug therapy following abdominal delivery in severe preeclampsia and normotensive pregnancy

Background

The imbalance between circulating concentrations of anti- and pro-angiogenic factors is usually intense in preeclampsia with severe features (sPE). It is possible that pre-delivery circulating levels of angiogenic factors in sPE may be associated with postpartum antihypertensive drug requirements.

Objective

To determine the predictive association between maternal pre-delivery serum concentrations of angiogenic factors and the use of ≥3 slow- and/or a rapid-acting antihypertensive drug therapy in sPE on postpartum days zero to three following caesarean delivery.

Study design

Women with sPE (n = 50) and normotensive pregnancies (n = 90) were recruited prior to childbirth. Serum samples were obtained from each participant < 48 hours before delivery to assess the concentrations of placental growth factor (PIGF) and soluble fms-like tyrosine kinase-1 (sFlt-1) using the Roche Elecsys platform. Each participant was followed up on postpartum days zero, one, two and three to monitor BP and confirm antihypertensive treatment. The optimal cut-off thresholds of sFlt-1/PIGF ratio from receiver operating characteristic curve predictive of the antihypertensive therapy were subjected to diagnostic accuracy assessment.

Results

The majority 58% (29/50) of sPE had multiple severe features of preeclampsia in the antenatal period with the commonest presentation being severe hypertension in 88% (44/50) of this group, followed by features of impending eclampsia which occurred in 42% (21/50). The median gestational age at delivery was 38 (Interquartile range, IQR 1) vs 36 (IQR 6) weeks, p < 0.001 in normotensive and sPE groups respectively. Notably, the median sFlt-1/PIGF ratio in normotensive and sPE groups were 7.3 (IQR 17.9) and 179.1 (IQR 271.2) respectively, p < 0.001. Of the 50 sPE participants, 34% (17/50) had early-onset preeclampsia. The median (IQR) of sFlt-1/PIGF in the early- and late-onset preeclampsia groups were 313.52 (502.25), and 166.59(195.37) respectively, p = 0.006. From postpartum days zero to three, 48% (24/50) of sPE received ≥ 3 slow- and/or a rapid-acting antihypertensive drug. However, the daily administration of ≥ 3 slow- and/or a rapid-acting antihypertensive drug in sPE were pre-delivery 26% (13/50), postpartum day zero 18% (9/50), postpartum day one 34% (17/50), postpartum day two 24% (12/50) and postpartum day three 20% (10/50). In sPE, the pre-delivery sFlt-1/PIGF ratio was predictive of administration of ≥3 slow- and/or a rapid-acting antihypertensive drug on postpartum days zero, one and two with the optimal cut-off ratio being ≥315.0, ≥181.5 and ≥ 267.8 respectively (sensitivity 72.7–75.0%, specificity 64.7–78.6%, positive predictive value 40.0–50.0% and negative predictive value 84.6% - 94.3%). The predictive performance of sFlt-1/PIG ratio on postpartum day 3 among the sPE was not statistically significant (area under receiver operating characteristic curve, 0.6; 95% CI, 0.3–0.8).

Conclusion

A pre-delivery sFlt-1/PIGF ratio (< 181.5) is a promising predictor for excluding the need for ≥3 slow- and/or a rapid-acting antihypertensive drug therapy in the immediate postpartum period in sPE.

Adiponectin Participates in Preeclampsia by Regulating the Biological Function of Placental Trophoblasts through P38 MAPK-STAT5 Pathway

BACKGROUND

We aimed to investigate the participation of adiponectin in preeclampsia, and to explore the possible mechanism.

METHODS

A total of 52 patients with preeclampsia and 30 normal women with full-term pregnancy were enrolled. Immunohistochemistry was used to detect the localization of MAPK and STAT5. RT-PCR was used to detect the expression of adiponectin mRNA in placental tissue of patients with preeclampsia and normal pregnant women. Western blot was used to detect the expression of adiponectin protein, MAPK, p-MAPK, STAT5 and p-STAT5 in placental tissue of patients with preeclampsia and normal pregnant women.

RESULTS

p-p38 was highly expressed in placental trophoblasts of patients with preeclampsia, while p-STAT5 was less expressed. Expression level of p-p38 and p-STAT5 in patients with preeclampsia were significantly different from those in normal pregnant women (P<0.01). Expression level of adiponectin mRNA was significantly lower in patients with preeclampsia than in normal pregnant women (P<0.05). Level of p-p38 expression was negatively correlated with levels of adiponectin expression (r=-0.413, P<0.05). Expression level of p-STAT5 was positively correlated with expression level of adiponectin (r=0.526, P<0.01).

CONCLUSION

Adiponectin participates in preeclampsia by regulating the biological function of placental tropho-blasts through p38 MAPK-STAT5 pathway.

Association of antepartum blood pressure levels and angiogenic profile among women with chronic hypertension

BACKGROUND

Angiogenic factors have been implicated in the pathogenesis of preeclampsia. This pilot study explored the association between antenatal blood pressure levels and angiogenic biomarkers (sFlt1 and PlGF) among women with chronic hypertension (cHTN).

METHODS

Blood samples were collected from women with cHTN (with/without superimposed preeclampsia) within 96 h prior to delivery. Subjects were stratified by mean outpatient BP as controlled (cBP < 140/90) or uncontrolled (uBP ≥ 140/90). Descriptive statistics were generated and assessed as appropriate. Logistic regression was employed to assess for adverse pregnancy outcomes between groups.

RESULTS

Data from seventy-eight women were analyzed, of which 58 (74.4%) were African American. Fifty-six (71.8%) had cBP and 22 (28.2%) had uBP. Use of antepartum outpatient antihypertensive medications was more frequent in patients with uBP (46.4% vs. 13.6%, p = 0.01). Compared to women with cBP, women with uBP had higher levels of pre-delivery sFlt1 and sFlt1/PlGF ratio (sFlt: 4218.5 vs. 3056.0 pg/ml, p = 0.046; sFlt/PlGF: 62.5 vs. 25.0, p = 0.04). Additionally, more uBP patients had superimposed preeclampsia with severe features (54.6% vs. 25.0%; p = 0.01) and preterm delivery (defined as a gestational age <35 weeks (40.9% vs. 10.7%; p = 0.002)) than cBP patients. In the multivariable model, women with uBP had greater odds of preterm delivery (OR 6.78; p = 0.01), superimposed preeclampsia (OR 3.20; p = 0.03) and preeclampsia with severe features (OR 3.27; p = 0.04) than women with cBP.

CONCLUSION

In women with cHTN, elevated antepartum BP is associated with worsened outcomes and may be associated with abnormal angiogenic profile at delivery. Larger studies are needed to confirm these findings.

Pravastatin for Preventing and Treating Preeclampsia: A Systematic Review

Importance

We have performed a systematic search to summarize the role of statins for preventing and treating severe preeclampsia.

Objective

The aim of this study was to examine whether pravastatin is a useful and safe alternative for treating preeclampsia during pregnancy.

Evidence Acquisition

A systematic MEDLINE (PubMed) search was performed (1979 to June 2017), which was restricted to articles published in English, using the relevant key words of "statins," "pregnancy," "preeclampsia," "obstetrical antiphospholipid syndrome," and "teratogenicity."

Results

The initial search provided 296 articles. Finally, 146 articles were related to the use of statins during pregnancy, regarding their effect on the fetus and the treatment of preeclampsia. Ten studies were related to in vitro studies, 25 in animals, and 24 in humans (13 case report series and 11 cohort studies). We found 84 studies on reviews of such guidelines on cardiovascular disease (35 studies), use of statins in the antiphospholipid syndrome (25 studies), statin's specific use during pregnancy (13 studies), or preeclampsia treatment (11 studies).

Conclusions

Although the studies are of poor quality, the rate of major congenital abnormalities in the newborn exposed to statins during pregnancy is no higher than the expected when compared with overall risk population. The review shows a potential beneficial role of statins in preventing and treating severe preeclampsia that needs to be evaluated through well-designed clinical trials.

Relevance

This update could influence positively the clinical practice, giving an alternative therapy for clinicians who treat preeclampsia, particularly in severe cases.

Pravastatin alleviates lipopolysaccharide-induced placental TLR4 over-activation and promotes uterine arteriole remodeling without impairing rat fetal development

Preeclampsia is associated with over-activation of the innate immune system in the placenta, in which toll-like receptor 4 (TLR4) plays an essential part. With their potent anti-inflammatory effects, statins have been suggested as potential prevention or treatment of preeclampsia, although evidence remains inadequate. Herewith, we investigated whether pravastatin could ameliorate preeclampsia-like phenotypes in a previously established lipopolysaccharide (LPS)-induced rat preeclampsia model, through targeting the TLR4/NF-κB pathway. The results showed that pravastatin reduced the blood pressure [maximum decline on gestational day (GD) 12, (101.33±2.49) mmHg vs. (118.3±1.37) mmHg, P<0.05] and urine protein level [maximum decline on GD9, (3,726.23±1,572.86)μg vs. (1,991.03±609.37)μg, P<0.05], which were elevated following LPS administration. Pravastatin also significantly reduced the rate of fetal growth restriction in LPS-treated rats (34.10% vs. 8.99%, P<0.05). Further pathological analyses suggested a restoration of normal spiral artery remodeling in preeclampsia rats by pravastatin treatment. These effects of pravastatin were associated with decreased TLR4/NF-κB protein levels in the placenta and IL-6/MCP-1 levels in serum. Additionally, no obvious abnormalities in fetal liver, brain, and kidney were found after administration of pravastatin. These results provide supportive evidence for use of pravastatin in preventing preeclampsia.

Acute Drug Effects on the Human Placental Tissue: The Development of a Placental Murine Xenograft Model

OBJECTIVE

A pilot study was conducted to establish a human placental xenograft, which could serve as a model to evaluate the effect of toxic exposures during pregnancy.

STUDY DESIGN

The protocol consisted of engraftment of third-trimester human placental tissue in immunocompromised mice, after induction of a pseudo-pregnancy state by ovariectomy and progesterone supplementation. To validate the model, the placental tissue before and after engraftment was examined by immunohistochemistry, fluorescence-activated cell sorting (FACS), single-nucleotide polymorphism (SNP) genotyping, and whole transcriptome sequencing (WTSS). The human chorion gonadotropin (hCG) production in serum and urine was examined by enzyme-linked immunosorbent assay.

RESULTS

Microscopic evaluation of the placental tissue before and after engraftment revealed a stable morphology and preserved histological structure of the human tissue. Viable trophoblast was present after engraftment and remained stable over time. Vascularization and hormonal secretion (hCG) were present till 3 weeks after engraftment. Thirty-one SNPs were equally present, and there was a stable expression level for 56 451 genes evaluated by whole transcriptome sequencing.

CONCLUSION

Although this human placental xenograft model cannot copy the unique uterine environment in which the placenta develops and interacts between the mother and the fetus, it could be a suitable tool to evaluate the acute impact and adaptive processes of the placental tissue to environmental changes.

The Role of Statins in Prevention of Preeclampsia: A Promise for the Future?

Preeclampsia has been linked to high morbidity and mortality during pregnancy. However, no efficient pharmacological options for the prevention of this condition are currently available. Preeclampsia is thought to share several pathophysiologic mechanisms with cardiovascular disease, which has led to investigations for the potential role of statins (HMG CoA reductase inhibitors) in its prevention and early management. Pravastatin seems to have a safer pharmacokinetic profile compared to other statins, however, the existing preclinical evidence for its effectiveness in preeclampsia treatment has been mostly restricted to animal models. This review aims to summarize the current data and delineate the potential future role of statins in the prevention and management of preeclampsia.