New approaches for managing preeclampsia: clues from clinical and basic research

Emerging pharmacologic interventions for pre-eclampsia treatment

INTRODUCTION

Pre-eclampsia is a serious pregnancy complication and a major global concern for the mortality of both mother and fetus. Existing symptomatic treatments do not delay disease progression; thus, timely delivery of the baby is the most effective measure. However, the risk of various maternal and fetal injuries remains.

AREAS COVERED

In this review, we summarize the potential strategies for pharmacologic interventions in pre-eclamptic therapy. Specifically, we discuss the pathophysiological process of various effective candidate therapeutics that act on potential pathways and molecular targets to inhibit key stages of the disease. We refer to this pathogenesis-focused drug discovery model as a pathogenesis-target-drug (P-T-D) strategy. Finally, we discuss the introduction of nanotechnologies to improve the safety and efficacy of therapeutics via their specific placental targeting ability and placental retention effects.

EXPERT OPINION

Despite the active development of novel pharmacological treatments based on our current knowledge of pre-eclamptic pathogenesis, investigations are still in the early phase. Thus, further exploration of the pathological mechanisms, integrated with the P-T-D strategy and novel nanosystems, could encourage the development of more effective and safer strategies. Such advances could lead to a shift from expectant management to mechanistic-based therapy for pre-eclampsia.

Nonlinear analysis of heart rhythm in preeclampsia: a route for translational clinical applications in neuroinflammation

Preeclampsia is a pregnancy-specific condition which gets detected through hypertension and excessive protein excretion in urine. While preeclampsia used to be regarded as a self-limiting maternal condition which resolved with the delivery of the placenta, it is nowadays considered a complex and multifactorial disease that affects the offspring. Unfortunately, the etiology and pathophysiology of this multifaceted disorder remain elusive. Recent findings have confirmed that an altered maternal autonomic function may play a vital role in developing preeclampsia in conjunction with an imbalanced maternal immune system. Additionally, further evidence supports the crucial role of an exacerbated immune response driven by a non-infectious trigger during preeclampsia. Therefore, as a sterile inflammation, the elucidation of the neuroinflammatory mechanisms of preeclampsia warrants obtaining relevant knowledge suitable for translational clinical applications.

Heart rate variability (HRV) is an affordable and non-invasive method for indirectly assessing the autonomic nervous system and the cholinergic anti-inflammatory pathway (CAP). Notably, the nonlinear analysis of HRV offers novel indexes to explore the neuroimmune interactions in diverse preclinical and clinical settings of inflammation. Given that the dynamics of HRV is nonlinear in health, we hypothesized that a neuroinflammatory condition in preeclampsia might be associated with changes in nonlinear features of maternal and fetal HRV. Thus, the present review aims to present evidence of the potential changes in maternal-fetal HRV associated with neuroinflammatory modifications in preeclamptic women. We considered that there is still a need for assessing the nonlinear features of maternal and fetal HRV as complementary biomarkers of inflammation in this population in future studies, being a potential route for translational clinical applications.

Tumour necrosis factor-α (TNF-α) serum levels in preeclampsia pregnant women and pregnant women at risk with preeclampsia

OBJECTIVE

This study aimed to determine serum tumour necrosis factor-α (TNF-α) levels in pregnant women with the risk of preeclampsia and those who have preeclampsia.

METHOD

This research was a cross-sectional study and conducted in two maternal and child hospitals in Makassar, South Sulawesi, Indonesia, that is Pertiwi and Fatimah hospitals. As many as 86 pregnant women; 31 normal blood pressure, 26 high-risk preeclampsia and 29 preeclampsia pregnant women checked their blood pressure and then gave informed consent. TNF-α level was examined used enzyme-linked immunosorbent assay (ELISA) in Hasanuddin University laboratorium. Pregnant women with antiplatelet therapy, infectious, and inflammatory diseases were excluded from the study. Data presented in the form of tables and narratives. The bivariate analysis presented in the form of a cross table between variables TNF-α levels with pregnant women at risk for preeclampsia and preeclampsia and analyzed used Kruskal Wallis Test.

RESULTS

TNF-α levels in normal patients are 24.47pg/ml, whereas those at the risk of preeclampsia appear two times higher than preeclampsia (57.052pg/ml), pregnant women with preeclampsia have approximately five times higher levels than normal pregnant women (327.330pg/ml).

CONCLUSION

Increased levels of TNF have begun to occur during the high-risk phase and have increased very high during preeclampsia.

Aspirin modulates STOX1 expression and reverses STOX1-induced insufficient proliferation and migration of trophoblast cells

BACKGROUND

A major cause of preeclampsia is the placental ischemia caused by insufficient trophoblast cells, invading into the spiral artery. Storkhead-box protein 1 (STOX1) is highly associated with preeclampsia. Meanwhile, low-dose aspirin for patients with preeclampsia is effective in reducing the incidence of preeclampsia. The aim of the present study was to explore the underlying mechanism, and the relationship between STOX1 and aspirin in preeclampsia.

METHODS

The human choriocarcinoma cell line JEG-3 was employed to mimic trophoblast cells and establish a model for trophoblast cells overexpressing STOX1 and knockdown of JEG cell lines, which were treated with aspirin afterwards. Cell counting kit-8 (CCK-8) assay was utilized to estimate cell proliferation and optimal concentration of aspirin for further experiments. Meanwhile, transwell assay was used to detect migration, and flow cytometry was used to measure apoptosis. Quantitative reverse transcription polymerase chain reaction (RT-qPCR) and Western blotting were applied to analyze the expression levels of STOX1 and related genes.

RESULTS

Overexpression of STOX1 inhibited proliferation of JEG-3 cells through epidermal growth factor (EGF), vascular EGF (VEGF), and transforming growth factor beta 1 (TGF-β1) proteins, while suppressed migration through MMP2, MMP9, and E-cadherin proteins. In contrast, apoptosis of JEG-3 cells was elevated by STOX1 through Bcl-2, Bax, and Cox-2 proteins. Furthermore, we found that aspirin modulated the expression level of STOX1 and reversed proliferation and migration of STOX1-induced insufficient trophoblast cells.

CONCLUSION

The present study suggested that inhibition of the expression of STOX1 could promote the effects of aspirin in the treatment of preeclampsia.

The diagnosis values of serum STAT4 and sEng in preeclampsia

Objective

To detect the levels of signal transducer and activator of transcription 4 (STAT4) and soluble endoglin (sEng) in preeclampsia patients and analyze the diagnostic values of STAT4 and sEng in preeclampsia.

Methods

Fifty‐four pregnant women with preeclampsia from October 2017 to June 2018 were included in this study. Twenty‐eight matched healthy pregnant women were set as the control group. The general clinical characteristics were measured. Serum STAT4 and sEng were detected by ELISA. Correlation between STAT4 and sEng, and their diagnostic value in preeclampsia were analyzed.

Results

Compared with control, the prothrombin time in preeclampsia was significantly lower, while the mean arterial pressure, 24‐hour urine protein, serum creatinine, fibrinogen, and ALT were significantly higher. The circulating levels of STAT4 and sEng were significantly increased in the preeclampsia. The serum levels of STAT4 and sEng in preeclampsia were positively correlated. For the diagnosis of preeclampsia by the serum STAT4, AUC is 0.902, and the sensitivity and specificity are 0.893 and 0.929. By the serum sEng, AUC is 0.873, and the sensitivity and specificity are 0.816 and 0.905.

Conclusion

The serum levels of STAT4 and sEng were significantly increased in preeclampsia with disease severity status, which have promise as diagnostic markers in preeclampsia.

A Non-Targeted LC-MS Profiling Reveals Elevated Levels of Carnitine Precursors and Trimethylated Compounds in the Cord Plasma of Pre-Eclamptic Infants

Preeclampsia (PE) is a complex pregnancy disorder. It is not extensively known how the metabolic alterations of PE women contribute to the metabolism of newborn. We applied liquid chromatography-mass spectrometry (LC-MS) based non-targeted metabolomics to determine whether the metabolic profile of plasma from umbilical cord differs between infants born to PE and non-PE pregnancies in the FINNPEC study. Cord plasma was available from 42 newborns born from PE and 53 from non-PE pregnancies. 133 molecular features differed between PE and non-PE newborns after correction for multiple testing. Decreased levels of 4-pyridoxic acid were observed in the cord plasma samples of PE newborns when compared to non-PE newborns. Compounds representing following areas of metabolism were increased in the cord plasma of PE newborns: urea and creatine metabolism; carnitine biosynthesis and acylcarnitines; putrescine metabolites; tryptophan metabolism and phosphatidylcholines. To our knowledge, this study is the first one to apply LC-MS based metabolomics in cord plasma of PE newborns. We demonstrate that this strategy provides a global picture of the widespread metabolic alterations associated with PE and particularly the elevated levels of carnitine precursors and trimethylated compounds appear to be associated with PE at birth.

Immunological Tolerance, Pregnancy, and Preeclampsia: The Roles of Semen Microbes and the Father

Although it is widely considered, in many cases, to involve two separable stages (poor placentation followed by oxidative stress/inflammation), the precise originating causes of preeclampsia (PE) remain elusive. We have previously brought together some of the considerable evidence that a (dormant) microbial component is commonly a significant part of its etiology. However, apart from recognizing, consistent with this view, that the many inflammatory markers of PE are also increased in infection, we had little to say about immunity, whether innate or adaptive. In addition, we focused on the gut, oral and female urinary tract microbiomes as the main sources of the infection. We here marshall further evidence for an infectious component in PE, focusing on the immunological tolerance characteristic of pregnancy, and the well-established fact that increased exposure to the father's semen assists this immunological tolerance. As well as these benefits, however, semen is not sterile, microbial tolerance mechanisms may exist, and we also review the evidence that semen may be responsible for inoculating the developing conceptus (and maybe the placenta) with microbes, not all of which are benign. It is suggested that when they are not, this may be a significant cause of PE. A variety of epidemiological and other evidence is entirely consistent with this, not least correlations between semen infection, infertility and PE. Our view also leads to a series of other, testable predictions. Overall, we argue for a significant paternal role in the development of PE through microbial infection of the mother via insemination.

Altered Endothelial Nitric Oxide Signaling as a Paradigm for Maternal Vascular Maladaptation in Preeclampsia

PURPOSE OF REVIEW

The goal of this review is to present the newest insights into what we view as a central failure of cardiovascular adaptation in preeclampsia (PE) by focusing on one clinically significant manifestation of maternal endothelial dysfunction: nitric oxide signaling. The etiology, symptoms, and current theories of the PE syndrome are described first, followed by a review of the available evidence, and underlying causes of reduced endothelial nitric oxide (NO) signaling in PE.

RECENT FINDINGS

PE maladaptations include, but are not limited to, altered physiological stimulatory inputs (e.g., estrogen; VEGF/PlGF; shear stress) and substrates (L-Arg; ADMA), augmented placental secretion of anti-angiogenic and inflammatory factors such as sFlt-1 and Eng, changes in eNOS (polymorphisms, expression), and reduced bioavailability of NO secondary to oxidative stress. PE is a complex obstetrical syndrome that is associated with maternal vascular dysfunction. Diminished peripheral endothelial vasodilator influence in general, and of NO signaling specifically, are key in driving disease progression and severity.

Pharmacogenetics in the treatment of pre-eclampsia: current findings, challenges and perspectives

Pre-eclampsia (PE) is defined as pregnancy-induced hypertension and proteinuria, and is a major cause of maternal and perinatal morbidity and mortality. A large subgroup of pregnant women with PE is nonresponsive to antihypertensive drugs, including methyldopa, nifedipine and hydralazine. Pharmacogenomics may help to guide the individualized therapy for this nonresponsive subgroup. However, just a few pharmacogenetic studies examined the effects of genetic polymorphisms on response to antihypertensive drugs in PE, and the criteria of responsiveness used to define responsive or nonresponsive subgroups to antihypertensive therapy should be replicated by others. We review these gene–drugs interactions, novel approaches to pharmacogenomics research and potential novel drugs for PE therapy. Finally, we discuss the challenges and perspectives of pharmacogenetics in the treatment of PE.

Remote Monitoring of Hypertension Diseases in Pregnancy: A Pilot Study

Background

Although remote monitoring (RM) has proven its added value in various health care domains, little is known about the remote follow-up of pregnant women diagnosed with a gestational hypertensive disorders (GHD).

Objective

The aim of this study was to evaluate the added value of a remote follow-up program for pregnant women diagnosed with GHD.

Methods

A 1-year retrospective study was performed in the outpatient clinic of a 2nd level prenatal center where pregnant women with GHD received RM or conventional care (CC). Primary study endpoints include number of prenatal visits and admissions to the prenatal observation ward. Secondary outcomes include gestational outcome, mode of delivery, neonatal outcome, and admission to neonatal intensive care (NIC). Differences in continuous and categorical variables in maternal demographics and characteristics were tested using Unpaired Student’s two sampled t test or Mann-Whitney U test and the chi-square test. Both a univariate and multivariate analysis were performed for analyzing prenatal follow-up and gestational outcomes. All statistical analyses were done at nominal level, Cronbach alpha=.05.

Results

Of the 166 patients diagnosed with GHD, 53 received RM and 113 CC. After excluding 5 patients in the RM group and 15 in the CC group because of the missing data, 48 patients in RM group and 98 in CC group were taken into final analysis. The RM group had more women diagnosed with gestational hypertension, but less with preeclampsia when compared with CC (81.25% vs 42.86% and 14.58% vs 43.87%). Compared with CC, univariate analysis in RM showed less induction, more spontaneous labors, and less maternal and neonatal hospitalizations (48.98% vs 25.00%; 31.63% vs 60.42%; 74.49% vs 56.25%; and 27.55% vs 10.42%). This was also true in multivariate analysis, except for hospitalizations.

Conclusions

An RM follow-up of women with GHD is a promising tool in the prenatal care. It opens the perspectives to reverse the current evolution of antenatal interventions leading to more interventions and as such to ever increasing medicalized antenatal care.

Placental growth factor: What hematologists need to know

Although first identified in placenta, the angiogenic factor known as placental growth factor (PlGF) can be widely expressed in ischemic or damaged tissues. Recent studies have indicated that PlGF is a relevant factor in the pathobiology of blood diseases including hemoglobinopathies and hematologic malignancies. Therapies for such blood diseases may one day be based upon these and ongoing investigations into the role of PlGF in sickle cell disease, acute and chronic leukemias, and complications related to hematopoietic cell transplantation. In this review, we summarize recent studies regarding the potential role of PlGF in blood disorders and suggest avenues for future research.

Validation of a Metallomics Analysis of Placenta Tissue by Inductively-Coupled Plasma Mass Spectrometry

Trace elements can play an important role in maternal health and fetal development, and deficiencies in some essential minerals including zinc and copper have been correlated in some individuals to the development of birth defects and adverse health outcomes later in life. The exact etiology of conditions like preeclampsia and the effects of fetal exposure to toxic metals has not been determined, making the assessment of trace element levels crucial to the elucidation of the causes of conditions like preeclampsia. Previous studies analyzing serum and placenta tissue have produced conflicting findings, suggesting the need for a robust, validated sample preparation and analysis method for the determination of trace elements in placenta. In this report, an acid digestion method and analysis by ICP-MS for a broad metallomics/mineralomics panel of trace elements is developed and validated over three experimental days for inter- and intraday precision and accuracy, linear range, matrix impact, and dilution verification. Spike recovery experiments were performed for the essential elements chromium (Cr), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), and zinc (Zn), and the toxic elements arsenic (As), cadmium (Cd), and lead (Pb) at levels equal to and in excess of native concentrations in control placenta tissue. The validated method will be essential for the development of scientific studies of maternal health and toxic metal exposure effects in childhood.

Heme oxygenase induction attenuates TNF-α-induced hypertension in pregnant rodents

Pre-eclampsia is a hypertensive disorder of pregnancy initiated by placental insufficiency and chronic ischemia. In response, several pathways activated in the placenta are responsible for the maternal syndrome, including increased production of the anti-angiogenic protein, sFlt-1, and inflammatory cytokines, especially tumor necrosis factor-alpha (TNF-α). Previous studies have demonstrated that heme oxygenase (HO) induction can block TNF-α pathways in vitro and attenuate placental ischemia-induced sFlt-1 in vivo. Here, we investigated whether HO-1 induction could attenuate TNF-α-induced hypertension in pregnant rats. In response to TNF-α infusion (100 ng/day i.p.), maternal mean arterial pressure (MAP) increased vs. control animals (104 ± 3 vs. 119 ± 3 mmHg). HO-1 induction had no effect in control animals, but significantly decreased MAP in TNF-α-infused animals (108 ± 2 mmHg). Placental vascular endothelial growth factor (VEGF) was decreased in response to TNF-α infusion (92 ± 4 vs. 76 ± 2 pg/mg). Placental sFlt-1 was increased by TNF-α infusion (758 ± 45 vs. 936 ± 46 pg/mg, p < 0.05), which trended to normalization by HO-1 induction (779 ± 98 pg/mg). In contrast, HO-1 induction had no significant effect on placental VEGF in TNF-α-infused animals. Taken together, these data suggest that one of the key mechanisms by which HO exerts cytoprotective actions in the placenta during inflammation due to chronic ischemia is through suppression of sFlt-1. Further work elucidating the bioactive metabolites of HO-1 in innate inflammatory responses to placental ischemia is warranted.

Emerging drugs for preeclampsia--the endothelium as a target

Preeclampsia, the development of new onset hypertension and proteinuria during pregnancy, affects ∼ 3 - 8% of all pregnancies and is a leading cause of maternal and perinatal morbidity and mortality. Despite the potentially devastating effects of this disease on the mother and the baby and the recent advances in understanding some of the pathological mechanisms responsible for the progression of preeclampsia, there are still few therapies available to manage the disease. The maternal syndrome of preeclampsia is characterized by systemic endothelial dysfunction; therefore, agents that improve endothelial function may hold promise to alleviate the symptoms of preeclampsia, delay the necessity for preterm delivery and improve neonatal outcomes. This brief review will focus on two therapies that are already approved for use in the US for other indications: PDE-5 inhibition to preserve nitric oxide - cGMP signaling to promote vasodilation and inhibition of the endothelin type A receptor to reduce vascular contraction.