Placental growth factor, vascular endothelial growth factor, and hypoxia-inducible factor-1α in the placentas of women with pre-eclampsia

Metabolic theory of preeclampsia: implications for maternal cardiovascular health

Preeclampsia (PE) is a multisystemic disorder of pregnancy that not only causes perinatal mortality and morbidity but also has a long-term toll on the maternal and fetal cardiovascular system. Women diagnosed with PE are at greater risk for the subsequent development of hypertension, ischemic heart disease, cardiomyopathy, cerebral edema, seizures, and end-stage renal disease. Although PE is considered heterogeneous, inefficient extravillous trophoblast (EVT) migration leading to deficient spiral artery remodeling and increased uteroplacental vascular resistance is the likely initiation of the disease. The principal pathophysiology is placental hypoxia, causing subsequent oxidative stress, leading to mitochondrial dysfunction, mitophagy, and immunological imbalance. The damage imposed on the placenta in turn results in the "stress response" categorized by the dysfunctional release of vasoactive components including oxidative stressors, proinflammatory factors, and cytokines into the maternal circulation. These bioactive factors have deleterious effects on systemic endothelial cells and coagulation leading to generalized vascular dysfunction and hypercoagulability. A better understanding of these metabolic factors may lead to novel therapeutic approaches to prevent and treat this multisystemic disorder. In this review, we connect the hypoxic-oxidative stress and inflammation involved in the pathophysiology of PE to the resulting persistent cardiovascular complications in patients with preeclampsia.

Hypoxia Inducible Factors (HIF1α and HIF3α) are differentially methylated in preeclampsia placentae and are associated with birth outcomes

Preeclampsia is a placental vascular pathology and hypoxia is known to influence placental angiogenesis. Hypoxia Inducible Factors (HIF1α and HIF3α) mediate the response to cellular oxygen concentration and bind to hypoxia response element of target genes. However the mechanism regulating above activity is not well-understood. We investigated if placental DNA methylation (DNAm) and expression of HIF1α and 3α genes are altered and associated with pre-eclampsia, placental weight and birth outcomes. Using a cohort comprising women with preeclampsia [N = 100, delivering at term (N = 43) and preterm (N = 57)] and normotensive controls (N = 100), we analysed DNAm in HIF1α and 3α, and their mRNA expression in placentae, employing pyrosequencing and quantitative real-time PCR, respectively. We observed significant hypermethylation at cg22891070 of HIF3α in preeclampsia placentae compared to controls (β = 1.5%, p = 0.04). CpG8 in the promoter region of HIF1α, showed marginally significant hypomethylation in preterm preeclampsia compared to controls (β = - 0.15%, p = 0.055). HIF1α expression was significantly lower in preterm preeclampsia compared to controls (mean ± SE = 10.16 ± 2.00 vs 4.25 ± 0.90, p = 0.04). Further, DNAm in HIF1α promoter region was negatively associated with its expression levels (β =  - 0.165, p = 0.024). Several CpGs in HIF1α were negatively associated with placental weight and birth outcomes including birth weight (β range =  - 0.224-0.300) and birth length [β range =  - 0.248 to - 0.301 (p < 0.05 for all)]. Overall, we demonstrate altered DNAm in HIF1α and HIF3α in preeclampsia placentae, also associated with various birth outcomes. Correlation of DNAm in HIF1α and its expression suggests a possible role in the pathogenesis of pre-eclampsia. Further investigations on interactions between HIF1α and HIF3α in preeclampsia would be interesting.

FtMt reduces oxidative stress-induced trophoblast cell dysfunction via the HIF-1α/VEGF signaling pathway

BACKGROUND

Preeclampsia (PE) is a complication of pregnancy that causes long-term adverse outcomes for the mother and fetus and may even lead to death. Oxidative stress caused by the imbalance of oxidants and antioxidants in the placenta has been considered as one of the key mechanisms of preeclampsia (together with inflammation, etc.), in which the placental mitochondria play an important role. The expression of hypoxia-inducible factor-1 (HIF-1α) and vascular endothelial growth factor (VEGF) is known to be increased in patients with PE. Mitochondrial ferritin (FtMt) is known to protect the mitochondria from oxidative stress, although its specific role in PE remains unclear.

METHODS

We used qRT-PCR and western blotting to detect the expression levels of FtMt, HIF-1α, and VEGF in placental tissues from patients with PE. Human chorionic trophoblast cells were also administered with hypoxia treatment, followed by the detection of cell proliferation, invasion and angiogenic capacity by CCK8, Transwell, and endothelial cell angiogenesis assays; we also detected the expression of HIF-1α and VEGF in these cells. Finally, overexpression or inhibitory FtMt lentiviral vectors, along with negative control vectors, were constructed and transfected into hypoxia-treated human chorionic trophoblast cells; this was followed by analyses of cell function.

RESULTS

The expression levels of FtMt, HIF-1α and VEGF in the PE group were higher than those in the control group (P < 0.05). Following hypoxia, there was an increase in the expression levels of HIF-1α and VEGF protein in trophoblast cells. There was also an increase in invasion ability and vascular formation ability along with a reduction in cell proliferation ability. These effects were reversed by transfecting cells with the knockout FtMt lentivirus vector. The differences were statistically significant.

CONCLUSION

Analyses showed that FtMt plays a key role in the vascular regulation of PE trophoblast cells after hypoxia possibly acting via the HIF-1α/VEGF signaling pathway. These results provide us an enhanced understanding of the pathogenesis of PE and suggest that the HIF-1α/VEGF signaling pathway represents a new target for the treatment of PE.

An insight into the placental growth factor (PlGf)/angii axis in Covid-19: a detrimental intersection

Coronavirus disease 2019 (Covid-19) is a recent and current infectious pandemic caused by severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2). Covid-19 may lead to the development of acute lung injury (ALI), acute respiratory distress syndrome (ARDS), and extrapulmonary manifestations in severe cases. Down-regulation of angiotensin-converting enzyme (ACE2) by the SARS-CoV-2 increases the production of angiotensin II (AngII), which increases the release of pro-inflammatory cytokines and placental growth factor (PlGF). PlGF is a critical molecule involved in vasculogenesis and angiogenesis. PlGF is stimulated by AngII in different inflammatory diseases through a variety of signaling pathways. PlGF and AngII are interacted in SARS-CoV-2 infection resulting in the production of pro-inflammatory cytokines and the development of Covid-19 complications. Both AngII and PlGF are interacted and are involved in the progression of inflammatory disorders; therefore, we aimed in this review to highlight the potential role of the PlGF/AngII axis in Covid-19.

Vascular endothelial growth factor and its receptors regulation in gestational diabetes mellitus and eclampsia

Background

An imbalance in the expression of vascular endothelial growth factor (VEGF) and its receptor (VEGF-R) during pregnancy plays an important role in the pathogenesis of gestational diabetes mellitus (GDM) and eclampsia. VEGF and its receptors change during the regulation of blood vessels as a result of risk factors such as familial genetics. These modifications include loss of original balance of serological indicators, upregulation or downregulation of growth factor indicators, and changes in the placenta, kidney, liver and other organs to varying degrees of damage. This has an impact on both the pregnant woman's and the fetus's health.

Main body

This paper summarizes the mechanisms of unbalanced VEGF and receptor expression based on data from relevant literature on GDM and eclampsia. An Imbalance in VEGF and its binding receptor is often associated with the occurrence of multiple pregnancy disorders. In recent years, researchers have focused on the potential role of VEGF and its receptors in the development of GDM and eclampsia.

Conclusion

This paper summarizes the different VEGF subtypes and their binding receptors, as well as mechanisms that cause GDM and eclampsia, in order to provide valuable data to inform monitoring, diagnosis, and prognosis.

Transcriptomic analysis of the chorioallantois in equine premature placental separation

BACKGROUND

Equine premature placental separation (PPS) is poorly understood and represents an important risk factor for fetal/neonatal hypoxia.

OBJECTIVES

To examine transcriptomic changes in the chorioallantois (CA) from mares with clinical PPS compared to the CA from normal foaling mares. Differential gene expression was determined and gene ontology as well as molecular pathways related to PPS were characterised.

STUDY DESIGN

Retrospective case: control study.

METHODS

CA were collected from Thoroughbred mares with a clinical history of PPS (n=33) and from control Thoroughbred mares (n=4) with normal parturition for examination of transcriptional changes in the placenta associated with PPS. Transcriptomic changes in the villous CA near the cervical star were determined by Illumina® sequencing and subsequent bioinformatic analysis. PPS samples were divided by k-means clustering, and differentially expressed genes (DEGs) in each PPS cluster were identified by comparing to controls. Shared DEGs between PPS clusters were used for gene ontology analysis and pathway analysis.

RESULTS

A total of 1204 DEGs were identified between PPS and control. Gene ontology revealed extracellular matrix (ECM) and cell adhesion, and pathway analysis revealed fatty acid, p-53, hypoxia, and inflammation. Eleven key regulator genes of PPS including growth factors (IGF1, TGFB2, TGFB3), transcription factors (HIF1A, JUNB, SMAD3), and transmembrane receptors (FGFR1, TNFRSF1A, TYROBP) were also identified.

MAIN LIMITATIONS

The use of clinical history of PPS, in the absence of other criteria, may have led to misidentification of some cases as PPS.

CONCLUSIONS

Transcriptomic analysis indicated that changes in ECM and cell adhesion were important factors in equine PPS. Key predicted upstream events include genes associated with hypoxia, inflammation and growth factors related to the pathogenesis of equine PPS.

Kisspeptin treatment improves fetal-placental development and blocks placental oxidative damage caused by maternal hypothyroidism in an experimental rat model

Maternal hypothyroidism is associated with fetal growth restriction, placental dysfunction, and reduced kisspeptin/Kiss1R at the maternal-fetal interface. Kisspeptin affects trophoblastic migration and has antioxidant and immunomodulatory activities. This study aimed to evaluate the therapeutic potential of kisspeptin in the fetal-placental dysfunction of hypothyroid Wistar rats. Hypothyroidism was induced by daily administration of propylthiouracil. Kisspeptin-10 (Kp-10) treatment was performed every other day or daily beginning on day 8 of gestation. Feto-placental development, placental histomorphometry, and expression levels of growth factors (VEGF, PLGF, IGF1, IGF2, and GLUT1), hormonal (Dio2) and inflammatory mediators (TNFα, IL10, and IL6), markers of hypoxia (HIF1α) and oxidative damage (8-OHdG), antioxidant enzymes (SOD1, Cat, and GPx1), and endoplasmic reticulum stress mediators (ATF4, GRP78, and CHOP) were evaluated on day 18 of gestation. Daily treatment with Kp-10 increased free T3 and T4 levels and improved fetal weight. Both treatments reestablished the glycogen cell population in the junctional zone. Daily treatment with Kp-10 increased the gene expression levels of Plgf, Igf1, and Glut1 in the placenta of hypothyroid animals, in addition to blocking the increase in 8-OHdG and increasing protein and/or mRNA expression levels of SOD1, Cat, and GPx1. Daily treatment with Kp-10 did not alter the higher protein expression levels of VEGF, HIF1α, IL10, GRP78, and CHOP caused by hypothyroidism in the junctional zone compared to control, nor the lower expression of Dio2 caused by hypothyroidism. However, in the labyrinth zone, this treatment restored the expression of VEGF and IL10 and reduced the GRP78 and CHOP immunostaining. These findings demonstrate that daily treatment with Kp-10 improves fetal development and placental morphology in hypothyroid rats, blocks placental oxidative damage, and increases the expression of growth factors and antioxidant enzymes in the placenta.

Interaction networks between the Fallopian tubes and the embryo in human tubal pregnancy: Current knowledge and perspectives

AIM

More than 90% of ectopic pregnancies occur in the Fallopian tubes. As the pathogenesis of tubal pregnancy remains largely unclear, the development of strategies to prevent and treat tubal pregnancy still represents a major clinical challenge. This review thoroughly summarizes the current data, aiming to determine the genes and signaling pathways that are involved in the pathophysiology of human tubal pregnancy.

METHODS

An electronic search from databases of PubMed, Google Scholar, and Chinese databases was carried out using key words pertaining to the pathogenesis of tubal pregnancy from the perspectives of both the Fallopian tubes and the embryo. A review of the literatures including review articles, experimental, and observational studies and case reports published between 1999 and 2021 was conducted.

RESULTS

Tubal pregnancy results from the interaction networks between the Fallopian tube and the embryo rather than from simple tubal abnormality. Furthermore, the embryo-maternal communication is supposed to start from the preimplantation period to the implantation period.

CONCLUSION

A greater understanding of the interaction networks between the Fallopian tubes and the embryo is of great significance for the prevention and medical treatment of tubal pregnancy.

Structural changes, increased hypoxia, and oxidative DNA damage in placenta due to maternal smokeless tobacco use

BACKGROUND

Smokeless tobacco (SLT) consumption during pregnancy is a well-recognized health risk that causes placental damage including hypoxia and oxidative damage. Although consumption of SLT by women varies from region to region, majority of tea leave pluckers consume SLT for relieving stress and pain. Still, the effects of SLT consumption have not been evaluated in tea garden workers (TGW). While previous studies have attempted to report effects of cigarette smoke using in vitro model, hypoxia-inducible factor (HIF)-1α expression in human placentae from pregnant women exposed to SLT has not been previously studied. This study was aimed to explore the effects of SLT consumption on placental structure, expression of HIF-1α and oxidative DNA damage in sample population of TGW.

METHODS

A total of 51 placentae were collected from SLT users and nonusers (n = 30 and 21, respectively) with full-term normal delivery, who were involved in the plucking of tea leaves during pregnancy in tea plantation. Low birth weight (LBW, i.e., weight <2,500 g) and normal birth weight (NBW) groups among both SLT user and nonuser were compared for the stated parameters. Placental tissues were processed for transmission electron microscopy (TEM) study and immunohistochemical analysis for the expression of HIF-1α and 8-hydroxy-2'-deoxyguanosine (8-OHdG).

RESULTS

Altered ultrastructural characteristics were observed in the tertiary villi of LBW group among SLT users which included endothelial cells protrusion into capillary lumen, degenerated nuclei, significant thickening of trophoblast basement membrane and vasculo-syncytial membrane, abnormalities of the microvilli, swollen or damaged mitochondria, and dilatation in endoplasmic reticulum cisternae. Furthermore, significant reduction in the perimeter, area, and number of the stromal capillary of the tertiary villi of placenta were found in LBW group as compared with NBW group from the SLT users. Enhanced expression for HIF-1α and oxidative DNA damage (8-OHdG) biomarker was observed in SLT users as compared with nonusers.

CONCLUSIONS

Maternal SLT exposure during pregnancy may be associated with villus hypoxia and consequently oxidative DNA damage. It is presumed that deleterious effect of SLT exposure on placenta could result in impairment of placental barrier, and restrict nutrient and oxygen supply from mother to fetus, and thus could be a cause of fetal growth restriction.

Recent Advances of MicroRNAs, Long Non-coding RNAs, and Circular RNAs in Preeclampsia

Preeclampsia is a clinical syndrome characterized by multiple-organ dysfunction, such as maternal hypertension and proteinuria, after 20 weeks of gestation. It is a common cause of fetal growth restriction, fetal malformation, and maternal death. At present, termination of pregnancy is the only way to prevent the development of the disease. Non-coding RNAs, including microRNAs, long non-coding RNAs, and circular RNAs, are involved in important pathological and physiological functions in life cycle activities including ontogeny, reproduction, apoptosis, and cell reprogramming, and are closely associated with human diseases. Accumulating evidence suggests that non-coding RNAs are involved in the pathogenesis of preeclampsia through regulation of various physiological functions. In this review, we discuss the current evidence of the pathogenesis of preeclampsia, introduce the types and biological functions of non-coding RNA, and summarize the roles of non-coding RNA in the pathophysiological development of preeclampsia from the perspectives of oxidative stress, hypoxia, angiogenesis, decidualization, trophoblast invasion and proliferation, immune regulation, and inflammation. Finally, we briefly discuss the potential clinical application and future prospects of non-coding RNA as a biomarker for the diagnosis of preeclampsia.

Serum hypoxia-inducible factor-1α and uterine artery Doppler ultrasound during the first trimester for prediction of preeclampsia

The objective of this study was to determine the predictive value of serum hypoxia-inducible factor-1α (HIF-1α) combined with uterine artery Doppler in singleton pregnancy during 11-13⁺⁶ weeks of gestation for preeclampsia. This prospective observational study was conducted in singleton pregnant women at 11-13⁺⁶ weeks of gestation who visited the King Chulalongkorn Memorial Hospital, Faculty of Medicine, Chulalongkorn University for antenatal care between February 2019 and May 2020. Serum HIF-1α levels and uterine artery Doppler ultrasound were performed. Pregnancy outcomes were recorded. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of these tests at the optimal cut-off values were determined to predict preeclampsia. A total of 385 participants were analyzed. Of these, 31 cases had preeclampsia (8.1%), and 6 cases of them had early-onset preeclampsia (1.6%). Preeclamptic women had significantly higher serum HIF-1α levels than normal pregnant women (median 1315.2 pg/ml vs. 699.5 pg/ml, p < 0.001). There was no difference in the mean pulsatility (PI) of the uterine artery. Serum HIF-1α levels were higher than 1.45 multiple of median for the gestational age as a cut-off value for predicting preeclampsia; the sensitivity, specificity, PPV, and NPV were 66.7%, 71.5%, 17.2%, and 96.2%, respectively. When a combination of abnormal serum HIF-1α levels and abnormal uterine artery Doppler PI (above the 95th percentile) were used as a predictive value to predict preeclampsia, the sensitivity, specificity, PPV, and NPV were 74.2%, 67.2%, 16.6%, and 96.8%, respectively. This study showed that the serum HIF-1α levels with or without uterine artery Doppler at 11-13⁺⁶ weeks of gestation were effective in predicting preeclampsia.

Increased pulsatility index of uterine artery Doppler between 26 and 28 weeks of gestation and adverse perinatal outcomes

OBJECTIVE

To compare adverse perinatal outcomes in pregnant women with or without normalization of the mean pulsatility index (PI) uterine artery Doppler between 24 and 28 weeks of gestation.

METHODS

Retrospective cohort which pregnant women were divided into three groups: normal uterine artery Doppler between 20-24 and 26-28 weeks (controls), abnormal uterine artery Doppler between 20-24 and normal between 26-28 weeks (anUtA), and abnormal uterine artery Doppler between 20-24 and 26-28 weeks (aaUtA). To compare adverse perinatal results between the groups Chi-square test was used. Binary logistic regression was used to assess the ability of uterine artery Doppler to predict birthweight < 10th and composite perinatal outcomes.

RESULTS

Birthweight was significantly lower in the aaUtA compared to anUtA (2687 vs 3248 grams, p = 0.0479). A significant negative correlation was observed between the mean PI uterine artery Doppler during the 3rd trimester and birthweight (r = -0.13, R ² = 0.035, p = .0192). The prevalence of composite perinatal outcomes was significantly higher in aaUtA compared to anUtA (25.9 vs 0%, p = .013). Mean PI uterine artery Doppler during the 3rd trimester was significant predictor for birthweight < 10th (OR: 2.74, CI 95% = 1.03-7.3), but the protodiastolic notch and the association between mean PI uterine artery Doppler and protodiastolic notch were not.

CONCLUSION

Maintenance of altered uterine artery Doppler during the 3rd trimester was associated with higher prevalence of composite perinatal outcomes and lower birthweight compared to its late normalization. Although modest, uterine artery Doppler in the 3rd trimester proved to be predictor of birthweight < 10th.

Adaptations of the human placenta to hypoxia: opportunities for interventions in fetal growth restriction

BACKGROUND

The placenta is the functional interface between the mother and the fetus during pregnancy, and a critical determinant of fetal growth and life-long health. In the first trimester, it develops under a low-oxygen environment, which is essential for the conceptus who has little defense against reactive oxygen species produced during oxidative metabolism. However, failure of invasive trophoblasts to sufficiently remodel uterine arteries toward dilated vessels by the end of the first trimester can lead to reduced/intermittent blood flow, persistent hypoxia and oxidative stress in the placenta with consequences for fetal growth. Fetal growth restriction (FGR) is observed in ∼10% of pregnancies and is frequently seen in association with other pregnancy complications, such as preeclampsia (PE). FGR is one of the main challenges for obstetricians and pediatricians, as smaller fetuses have greater perinatal risks of morbidity and mortality and postnatal risks of neurodevelopmental and cardio-metabolic disorders.

OBJECTIVE AND RATIONALE

The aim of this review was to examine the importance of placental responses to changing oxygen environments during abnormal pregnancy in terms of cellular, molecular and functional changes in order to highlight new therapeutic pathways, and to pinpoint approaches aimed at enhancing oxygen supply and/or mitigating oxidative stress in the placenta as a mean of optimizing fetal growth.

SEARCH METHODS

An extensive online search of peer-reviewed articles using PubMed was performed with combinations of search terms including pregnancy, placenta, trophoblast, oxygen, hypoxia, high altitude, FGR and PE (last updated in May 2020).

OUTCOMES

Trophoblast differentiation and placental establishment are governed by oxygen availability/hypoxia in early pregnancy. The placental response to late gestational hypoxia includes changes in syncytialization, mitochondrial functions, endoplasmic reticulum stress, hormone production, nutrient handling and angiogenic factor secretion. The nature of these changes depends on the extent of hypoxia, with some responses appearing adaptive and others appearing detrimental to the placental support of fetal growth. Emerging approaches that aim to increase placental oxygen supply and/or reduce the impacts of excessive oxidative stress are promising for their potential to prevent/treat FGR.

WIDER IMPLICATIONS

There are many risks and challenges of intervening during pregnancy that must be considered. The establishment of human trophoblast stem cell lines and organoids will allow further mechanistic studies of the effects of hypoxia and may lead to advanced screening of drugs for use in pregnancies complicated by placental insufficiency/hypoxia. Since no treatments are currently available, a better understanding of placental adaptations to hypoxia would help to develop therapies or repurpose drugs to optimize placental function and fetal growth, with life-long benefits to human health.

Elevated MicroRNA 183 Impairs Trophoblast Migration and Invasiveness by Downregulating FOXP1 Expression and Elevating GNG7 Expression during Preeclampsia

Preeclampsia (PE) is a hypertensive disorder of uncertain etiology that is the leading cause of maternal and fetal morbidity or mortality. The dysregulation of microRNAs (miRNAs) has been highlighted as a potential factor involved in the development of PE. Therefore, our study investigated a novel miRNA, miRNA 183 (miR-183), and its underlying association with PE. Expression of miR-183, forkhead box P1 (FOXP1), and G protein subunit gamma 7 (GNG7) in placental tissues of patients with PE was determined. Gain- and loss-of-function experiments were conducted to explore modulatory effects of miR-183, FOXP1, and GNG7 on the viability, invasion, and angiogenesis of trophoblast cells in PE. Finally, we undertook in vivo studies to explore effects of FOXP1 in the PE model. The results revealed suppressed expression of FOXP1 and significant elevations in miR-183 and GNG7 expression in placental tissues of PE patients. FOXP1 was observed to promote proliferation, invasion, and angiogenesis in human chorionic trophoblastic cells. miR-183 resulted in depletion of FOXP1 expression, while FOXP1 was capable of restraining GNG7 expression and promoting the mTOR pathway. The findings confirmed the effects of FOXP1 on PE. In conclusion, miR-183 exhibits an inhibitory role in PE through suppression of FOXP1 and upregulation of GNG7.

PlGF Immunological Impact during Pregnancy

During pregnancy, the mother’s immune system has to tolerate the persistence of paternal alloantigens without affecting the anti-infectious immune response. Consequently, several mechanisms aimed at preventing allograft rejection, occur during a pregnancy. In fact, the early stages of pregnancy are characterized by the correct balance between inflammation and immune tolerance, in which proinflammatory cytokines contribute to both the remodeling of tissues and to neo-angiogenesis, thus, favoring the correct embryo implantation. In addition to the creation of a microenvironment able to support both immunological privilege and angiogenesis, the trophoblast invades normal tissues by sharing the same behavior of invasive tumors. Next, the activation of an immunosuppressive phase, characterized by an increase in the number of regulatory T (Treg) cells prevents excessive inflammation and avoids fetal immuno-mediated rejection. When these changes do not occur or occur incompletely, early pregnancy failure follows. All these events are characterized by an increase in different growth factors and cytokines, among which one of the most important is the angiogenic growth factor, namely placental growth factor (PlGF). PlGF is initially isolated from the human placenta. It is upregulated during both pregnancy and inflammation. In this review, we summarize current knowledge on the immunomodulatory effects of PlGF during pregnancy, warranting that both innate and adaptive immune cells properly support the early events of implantation and placental development. Furthermore, we highlight how an alteration of the immune response, associated with PlGF imbalance, can induce a hypertensive state and lead to the pre-eclampsia (PE).

Comparison of VEGF-A values between pregnant women with COVID-19 and healthy pregnancies and its association with composite adverse outcomes

The aim is to compare VEGF-A values between pregnant women with coronavirus disease 2019 (COVID-19) and healthy controls. Furthermore, the association of inflammation parameters, disease severity, and obstetric complications with VEGF-A was investigated. This prospective case-control study was conducted on pregnant women who were admitted to Ankara City Hospital between June 14, 2020 and August 28, 2020. Pregnant women with COVID-19 (n = 95) were compared with a control group of healthy pregnant women (n = 92) with similar clinical and demographic characteristics. Demographic features, clinical characteristics, laboratory test results, VEGF-A values were compared between the groups. A correlation analysis was performed between VEGF-A levels, inflammation parameters, and clinical characteristics of the cases for pregnant women with COVID-19. VEGF-A levels were also compared between patients with composite adverse outcome and patients without any complication in the COVID-19 group. The two groups were similar except for obstetric complications (p > .05). The obstetric complication rate was higher in the COVID-19 group (p =.02). The two groups were comparable in terms of neutrophil to lymphocyte ratio and VEGF-A values. VEGF-A values were slightly different between the trimesters. A negative moderate statistically significant correlation was found between the neutrophil and VEGF-A values (r = -0.231, p =.02). VEGF-A values were similar between patients with and without composite adverse outcomes (p > .05). VEGF-A values were similar between pregnant women with COVID-19 and healthy controls.

Preeclampsia may influence offspring neuroanatomy and cognitive function: a role for placental growth factor†

Preeclampsia (PE) is a common pregnancy complication affecting 3-5% of women. Preeclampsia is diagnosed clinically as new-onset hypertension with associated end organ damage after 20 weeks of gestation. Despite being diagnosed as a maternal syndrome, fetal experience of PE is a developmental insult with lifelong cognitive consequences. These cognitive alterations are associated with distorted neuroanatomy and cerebrovasculature, including a higher risk of stroke. The pathophysiology of a PE pregnancy is complex, with many factors potentially able to affect fetal development. Deficient pro-angiogenic factor expression is one aspect that may impair fetal vascularization, alter brain structure, and affect future cognition. Of the pro-angiogenic growth factors, placental growth factor (PGF) is strongly linked to PE. Concentrations of PGF are inappropriately low in maternal blood both before and during a PE gestation. Fetal concentrations of PGF appear to mirror maternal circulating concentrations. Using Pgf-/- mice that may model effects of PE on offspring, we demonstrated altered central nervous system vascularization, neuroanatomy, and behavior. Overall, we propose that development of the fetal brain is impaired in PE, making the offspring of preeclamptic pregnancies a unique cohort with greater risk of altered cognition and cerebrovasculature. These individuals may benefit from early interventions, either pharmacological or environmental. The early neonatal period may be a promising window for intervention while the developing brain retains plasticity.

Levels of serum Hoxb3 and sFlt-1 in pre-eclamptic patients and their effects on pregnancy outcomes

AIM

We aimed to explore a new approach and theoretical basis for the diagnosis, treatment and prognosis of pre-eclampsia.

METHODS

In total, 103 pre-eclamptic patients (study group: SG) and 100 healthy pregnant women (control group: CG) were enrolled. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression level of serum Hoxb3. Enzyme-linked immunosorbent assay was used to detect the content of serum sFlt-1. Pregnancy outcomes in the two groups were recorded, and the correlations of the levels of Hoxb3 and sFlt-1 with the pregnancy outcomes were analyzed.

RESULTS

The relative expression of serum Hoxb3 mRNA in the CG was significantly higher than that in the SG, whereas the content of serum sFlt-1 in the CG was significantly lower than that in the SG. Compared with the CG, the SG had a significantly lower number of spontaneous deliveries, higher number of cesarean deliveries and significantly higher number of uneventful perinatal births. The incidences of intrauterine growth restriction, intrauterine distress, premature infants and neonatal deaths in perinatal infants in the SG were significantly higher than those in the CG. According to the analysis of receiver operating characteristic curves, the areas under the curves of Hoxb3, sFlt-1 and their combined detection for diagnosing pre-eclampsia were 0.799, 0.856 and 0.930, respectively. The areas under the curves for predicting poor perinatal outcomes were 0.724, 0.828 and 0.871, respectively.

CONCLUSION

In conclusion, Hoxb3 and sFlt-1 have certain reference significance for the risk evaluation of pre-eclampsia and the adverse pregnancy outcomes of pre-eclampsia women.

From animal models to patients: the role of placental microRNAs, miR-210, miR-126, and miR-148a/152 in preeclampsia

Placental microRNAs (miRNAs) regulate the placental transcriptome and play a pathological role in preeclampsia (PE), a hypertensive disorder of pregnancy. Three PE rodent model studies explored the role of placental miRNAs, miR-210, miR-126, and miR-148/152 respectively, by examining expression of the miRNAs, their inducers, and potential gene targets. This review evaluates the role of miR-210, miR-126, and miR-148/152 in PE by comparing findings from the three rodent model studies with in vitro studies, other animal models, and preeclamptic patients to provide comprehensive insight into genetic components and pathological processes in the placenta contributing to PE. The majority of studies demonstrate miR-210 is upregulated in PE in part driven by HIF-1α and NF-κBp50, stimulated by hypoxia and/or immune-mediated processes. Elevated miR-210 may contribute to PE via inhibiting anti-inflammatory Th2-cytokines. Studies report an up- and downregulation of miR-126, arguably reflecting differences in expression between cell types and its multifunctional capacity. MiR-126 may play a pro-angiogenic role by mediating the PI3K-Akt pathway. Most studies report miR-148/152 family members are upregulated in PE. Evidence suggests they may inhibit DNA methylation of genes involved in metabolic and inflammatory pathways. Given the genetic heterogeneity of PE, it is unlikely that a single placental miRNA is a suitable therapeutic target for all patients. Investigating miRNAs in PE subtypes in patients and animal models may represent a more appropriate approach going forward. Developing methods for targeting placental miRNAs and specific placental cell types remains crucial for research seeking to target placental miRNAs as a novel treatment for PE.

Salvia miltiorrhiza stem-leaf active components of salvianolic acids and flavonoids improved the hemorheological disorder and vascular endothelial function on microcirculation dysfunction rats

Microcirculation, which connects macrocirculation and cells between arterioles and venules, plays a major role in the early onset of a variety of diseases. In this article, a dextran-induced microcirculation dysfunction (MCDF) model rats were adopted to evaluate the effects and mechanism of Salvia miltiorrhiza stem-leaf extracts based on plasma and urine metabonomics. The results showed the effective components of S. miltiorrhiza stem-leaf could significantly improve the hemorheology and coagulation index of MCDF rats and callback the expression of endothelin-1 (ET-1), induciblenitric oxide synthase (iNOS), vascularendothelial growth factor (VEGF), P-Selectin, thromboxane A2, 6-keto-PGF_1α , TNF-α, and interleukin-1β to control group in MCDF rats. The decrease of microvessel density (MVD) in lung and thymus caused by MCDF was upgraded by Salvia miltiorrhiza stem-leaf. Based on the plasma and urine metabolic data, 20 potential biomarkers were identified. These biomarkers are mainly related to linoleic acid metabolism, glutathione metabolism, pantothenate and coenzyme A biosynthesis, pentose and glucuronate interconversions, pyruvate metabolism, glyoxylate and dicarboxylate metabolism, beta-alanine metabolism, and citrate cycle. The results indicated that the effective components of S. miltiorrhiza stem-leaf can improve the hemorheological disorder and vascular endothelial function. Meanwhile, the effective components can regulate potential biomarkers and correlated metabolic pathway, which can provide guidance for the research and development of new drugs for MCDF.

Circadian clock gene Clock is involved in the pathogenesis of preeclampsia through hypoxia

OBJECTIVE

To study the effect of the circadian clock gene Clock on the biological behavior of trophoblasts and its role in the pathogenesis of preeclampsia.

METHODS

Quantitative real-time polymerase chain reaction (RT-qPCR) was used to detect the expression of Clock mRNA. Western blot and immunohistochemistry were used to detect the expression and localization of Clock protein. CoCl₂ was used to induce the hypoxic trophoblast cells. Cell invasion assay, wound healing assay and MTT assays were used to detect the invasion, migration, and proliferation ability. Reduced uterine perfusion pressure (RUPP) rat model was established by surgically clamping the abdominal aorta and uterine arteries. Transfection of si-Clock was used to silencing the expression of Clock.

RESULTS

Clock mRNA expression was increased in placenta of preeclampsia and CoCl₂-induced hypoxic trophoblasts, while protein was decreased. But the trend was opposite in RUPP rat models. Hypoxia can also change the expression rhythm of Clock. The proliferation, migration and invasion ability of trophoblasts decreased after hypoxia, while these abilities restored to near normal level after silencing Clock.

CONCLUSION

The expression of Clock gene in human placenta tissue, hypoxia cell model and RUPP rat model suggests that it may regulate the biological behavior of trophoblast cells through hypoxia, and then participate in the pathogenesis of preeclampsia.

Association of VEGFA and IL1β gene polymorphisms with preeclampsia in Sudanese women

Background

Preeclampsia can lead to adverse maternal and perinatal outcomes. There are few studies on the genetic factors associated with preeclampsia in Africa in general and in Sudan in specific.

Methods

A case–control study (60 women in each arm) was conducted at Saad Abualila Hospital in Khartoum, Sudan, from March to September 2018. The participants were genotyped for vascular endothelial growth factor A (VEGFA) rs3025039, interleukin 1 beta (IL1β) rs16944, and IL1β rs1143634 by performing polymerase chain reaction–restriction fragment length polymorphism analysis, and the results were confirmed by DNA sequencing.

Results

There was no significant difference in the age, parity, body mass index, or other characteristics tested between the preeclampsia group and the control group (60 women in each arm). The rs3025039, rs16944, and rs1143634 genotypes were distributed in accordance with Hardy–Weinberg equilibrium (p > .05). For rs3025039, CT, CT+TT, and the T allele were risk factors for preeclampsia (odds ratio [OR] = 2.4; 95% CI [1.12–5.32]; p = .02; OR = 2.49 [1.17–25.27]; p = .01; OR = 2.05; 95% CI [1.10–3.83]; p = .02, respectively). Regarding rs16944, only the heterozygous genotype CT was associated with preeclampsia (OR = 2.55; 95% CI [1.15–5.56]; p = .01). Regarding rs1143634, CT, CT+TT, and the T allele were risk factors for preeclampsia (OR = 5.28; 95% CI [2.26–12.33]; p < .001; OR = 4.50; 95% CI [2.06–9.81]; p < .001; OR = 2.75; 95% CI [1.48–5.12]; p = .001, respectively).

Conclusion

Polymorphisms in IL1β and VEGFA were associated with preeclampsia in this setting. Significant associations were observed between preeclampsia and rs3025039, rs16944, and rs1143634.