Recent insights into the pathophysiology of preeclampsia

Maternal prediabetes as a risk factor of preeclampsia and placental dysfunction in pregnant female Sprague-Dawley rats

BACKGROUND

Prediabetes (PD) is associated with intermediate hyperglycaemia, dyslipidaemia, reduced nitric oxide (NO) bioavailability and moderate hypertension. All these factors are risk factor for preeclampsia (PE). However, the effects of the PD on placental function have not been shown. Accordingly, this study sought to investigate a possible link between maternal PD and the risk of developing PE.

METHODS

Pregnant female Sprague-Dawley rats (N = 18) were divided into normal, preeclamptic and prediabetic groups (n = 6 in each group) to study the effects of maternal PD on placenta function over the period of 19 days. Blood glucose and blood pressure were measured on gestational day (GND) 0, 9 and 18. Placental vascular endothelial growth factor (VEGF), placenta growth factor (PlGF) and soluble fms-like tyrosine kinase 1 (sFlt-1) mRNA expression were measured terminally. Data were analysed using ANOVA followed by the Tukey-Kramer post hoc test. Values of p < .05 were used to indicate statistical significance.

RESULTS

Maternal PD and PE significantly increased blood glucose, decrease NO concentration and increase in MAP by comparison to the normal pregnant control group. Maternal PD significantly decreased VEGF, PlGF mRNA expression with a slight increase in sFlt-1 mRNA expression comparison to the normal pregnant control group.

CONCLUSIONS

Maternal PD is associated with placental dysfunction due to impaired glucose handling, endothelial dysfunction and an imbalance in angiogenic and antiangiogenic factors. Therefore, maternal PD is a risk factor of PE.

Association of Prepregnancy Cardiometabolic Health With Hypertensive Disorders of Pregnancy Among Historically Underrepresented Groups in the United States

BACKGROUND

Prepregnancy diabetes and obesity are associated with hypertensive disorders of pregnancy (HDPs). However, the proportion of cases of HDP in the population explained by diabetes and obesity (population attributable fraction), especially among American Indian and Alaska Native and Native Hawaiian and Other Pacific Islander, is not well characterized.

METHODS AND RESULTS

We conducted a cross-sectional analysis of data on individuals with a live singleton birth from the US National Vital Statistics System between 2016 and 2019. We used adjusted logistic regression to estimate the prevalence odds ratios of HDPs and tested interaction for race and ethnicity. We calculated the population attributable fraction for the effect of obesity and diabetes on HDPs. Among 13 201 338 birthing individuals, (mean age, 29±6 years), 7% had HDP. The prevalence of HDP was highest among American Indian and Alaska Native individuals (9.1%). Prepregnancy diabetes (prevalence odds ratio, 2.63 [95% CI, 2.59-2.67]) and obesity (prevalence odds ratio, 2.95 [95% CI, 2.93-2.97]) were associated with HDPs. Compared with non-Hispanic White individuals, the association of diabetes with HDPs was strongest among Native Hawaiian and Other Pacific Islander (prevalence odds ratio, 3.05 [95% CI, 2.48-3.77]), and the association of obesity with HDP was strongest among Asian individuals (prevalence odds ratio, 3.44 [95% CI, 3.35-3.54]; all P for interaction <0.05). Population attributable fractions for diabetes and obesity were highest among Native Hawaiian and Other Pacific Islander individuals (diabetes, 3.7% [95% CI, 3.3%-4.0%]; and obesity, 45% [95% CI, 41.9%-47.8%]).

CONCLUSIONS

Prepregnancy diabetes and obesity are associated with HDP across all racial and ethnic groups. Diabetes and obesity have highest population attributable fractions among Native Hawaiian and Other Pacific Islander individuals and should be aggressively targeted during childhood, adolescence, and young adulthood to reduce risk of HDPs.

The role of T cell stimulated agonistic autoantibodies to the angiotensin II type I receptor (AT1-AA) in mediating multiorgan dysfunction in IL-17 induced hypertension during pregnancy

PROBLEM

Preeclampsia (PE), new-onset hypertension during pregnancy accompanied by organ dysfunction, is associated with chronic inflammation including elevated IL-17, CD4+ T cells, B cells and natural killer (NK) cells. IL-17 can serve as a signal for either the adaptive or innate immune activation. We have previously shown that IL-17 contributes to increased blood pressure in association with elevated TH17 cells, NK cells and B cells secreting angiotensin II type 1 receptor agonistic autoantibodies (AT1-AA) during pregnancy. Moreover, we have shown an important role for CD4+T cells and AT1-AA in multiorgan dysfunction as measured by mitochondrial oxidative stress (mt ROS). However, we do not know the role of adaptive immune cells such as T cells or B cells secreting AT1-AA in mediating the PE phenotype in response to elevated IL-17.

METHOD OF STUDY

In order to answer this question, we infused IL-17 (150 pg/day i.p.) into either Sprague Dawley (SD) or athymic nude rats via mini-osmotic pump from gestational day (GD) 14-19 of pregnancy. On GD 19, blood pressure was determined and NK cells, mtROS and respiration and AT1-AA production from B cells were measured.

RESULTS

Infusion of IL-17 increased blood pressure in the presence or absence of T cells. Mean arterial pressure (MAP) increased with IL-17 from 98 ± 2 mm Hg (n = 12) to 114 ± 2 (n = 12) in SD rats and from 99 ± 4 mm Hg (n = 7) versus 115 ± 2 mm Hg (n = 7) in athymic nude rats. Similar trends were seen in NK cells and placental mt ROS. Knowing that IL-17 stimulates AT1-AA in SD pregnant rats, we included a group of SD and athymic nude pregnant rats infused with IL-17 and the AT1-AA inhibitor peptide ('n7AAc'). The inhibitor attenuated blood pressure (104.9 ± 3.2, p = .0001) and normalized NK cells and mt function in SD pregnant rats. Importantly, the AT1-AA was not produced in pregnant nude IL-17 treated rats, nor did 'n7AAc' effect MAP, in nude athymic rats.

CONCLUSION

These findings suggest two conclusions; one is that IL-17 causes hypertension and multiorgan dysfunction in the absence of T cells and AT1-AA, possibly through its activation of innate cells and secondly, in the presence of T cells, blockade of the AT1-AA attenuates the effect of IL-17. This study indicates the critical effects of elevated IL-17 during pregnancy and suggest treatment modalities to consider for PE women.

MTHFR A1298C polymorphism: a predictor of reduced risk of preeclampsia in Punjab, Pakistan

OBJECTIVES

This study aimed to investigate the genetic association between MTHFR (A1298C) SNP and preeclampsia (PE) in Punjab, Pakistan.

METHODS

A sample of 80 pregnant women (40 healthy pregnant women and 40 with PE) was pooled for genotyping MTHFR A1298C polymorphism by using the tetra-primer amplification refractory mutation system (ARMS) PCR. The Genotypic and allelic assessments were performed using various statistical techniques.

RESULTS

The AC genotype and C allele of MTHFR A1298C were found to be associated with decreased risk of PE (odds ratio [OR]: 0.31, risk ratio [RR]: 0.58, p = 0.01), and (odds ratio [OR]: 0.49, risk ratio [RR]: 0.61, p = 0.04), respectively.

CONCLUSION

In conclusion, genetic polymorphism A1298C in MTHFR may pose a protective effect in the studied population.

Association of plasma Decorin levels and markers of glycocalyx disruption with adverse events in women with severe preeclampsia

Identifying preeclamptic women with an increased risk of severe maternal complications can aid in timely interventions to optimize pregnancy outcomes. Newer biomarkers such as Decorin and markers of endo glycocalyx disruption were assessed in earlier studies for its role in predicting preeclampsia, but their role in identifying those with adverse maternal outcomes is limited. This study aimed to evaluate the association of these biomarkers with adverse maternal outcomes in women with severe pre-eclampsia. Markers of glycocalyx disruption may be further explored for their role along with clinical features and other biomarkers in identifying women at higher risk of maternal complications.

From Molecules to Imaging: Assessment of Placental Hypoxia Biomarkers in Placental Insufficiency Syndromes

Placental hypoxia poses significant risks to both the developing fetus and the mother during pregnancy, underscoring the importance of early detection and monitoring. Effectively identifying placental hypoxia and evaluating the deterioration in placental function requires reliable biomarkers. Molecular biomarkers in placental tissue can only be determined post-delivery and while maternal blood biomarkers can be measured over time, they can merely serve as proxies for placental function. Therefore, there is an increasing demand for non-invasive imaging techniques capable of directly assessing the placental condition over time. Recent advancements in imaging technologies, including photoacoustic and magnetic resonance imaging, offer promising tools for detecting and monitoring placental hypoxia. Integrating molecular and imaging biomarkers may revolutionize the detection and monitoring of placental hypoxia, improving pregnancy outcomes and reducing long-term health complications. This review describes current research on molecular and imaging biomarkers of placental hypoxia both in human and animal studies and aims to explore the benefits of an integrated approach throughout gestation.

RUPP Th17s cause hypertension and mitochondrial dysfunction in the kidney and placenta during pregnancy

BACKGROUND

Preeclampsia (PE), new-onset hypertension (HTN), and organ dysfunction during the second half of pregnancy, is associated with an increase in inflammatory immune cells, including T helper 17 (Th17) cells. Studies have demonstrated that mitochondrial (mt) dysfunction is important in the pathogenesis of PE though causative factors have yet to be fully identified. Although Th17 cells, natural killer (NK) cells, and mt dysfunction contribute to HTN in the reduced uterine perfusion pressure (RUPP) rat model, the role of Th17 cells or IL-17 in mt dysfunction is unknown. Therefore, we hypothesize that RUPP stimulated Th17 cells cause HTN and mt dysfunction, which is alleviated with the blockade of IL-17.

METHODS

On gestational day 12 (GD12), RUPP Th17 cells were transferred into normal pregnant (NP) Sprague Dawley rats. A subset of NP + RUPPTh17 rats received IL-17RC (100 pg/day) on GD14-19. Blood pressure (MAP), NK cells, and mt function were measured on GD19 in all groups.

RESULTS

MAP increased in response to NP + RUPP Th17 compared to NP rats and was lowered with IL-17RC. Circulating and placental NK cells increased with NP + RUPP Th17 compared to NP and were lowered with IL-17RC. Renal mtROS increased in NP + RUPP Th17 compared to NP and was normalized with IL-17RC. Similar to PE women, placental mtROS decreased in NP + RUPP Th17 and was normalized with IL-17RC.

CONCLUSION

Our results indicate that IL-17RC inhibition normalizes HTN, NK cell activation, and multi-organ mt dysfunction caused by Th17 cells stimulated in response to placental ischemia.

Pre-eclampsia

Pre-eclampsia is a life-threatening disease of pregnancy unique to humans and a leading cause of maternal and neonatal morbidity and mortality. Women who survive pre-eclampsia have reduced life expectancy, with increased risks of stroke, cardiovascular disease and diabetes, while babies from a pre-eclamptic pregnancy have increased risks of preterm birth, perinatal death and neurodevelopmental disability and cardiovascular and metabolic disease later in life. Pre-eclampsia is a complex multisystem disease, diagnosed by sudden-onset hypertension (>20 weeks of gestation) and at least one other associated complication, including proteinuria, maternal organ dysfunction or uteroplacental dysfunction. Pre-eclampsia is found only when a placenta is or was recently present and is classified as preterm (delivery <37 weeks of gestation), term (delivery ≥37 weeks of gestation) and postpartum pre-eclampsia. The maternal syndrome of pre-eclampsia is driven by a dysfunctional placenta, which releases factors into maternal blood causing systemic inflammation and widespread maternal endothelial dysfunction. Available treatments target maternal hypertension and seizures, but the only 'cure' for pre-eclampsia is delivery of the dysfunctional placenta and baby, often prematurely. Despite decades of research, the aetiology of pre-eclampsia, particularly of term and postpartum pre-eclampsia, remains poorly defined. Significant advances have been made in the prediction and prevention of preterm pre-eclampsia, which is predicted in early pregnancy through combined screening and is prevented with daily low-dose aspirin, starting before 16 weeks of gestation. By contrast, the prediction of term and postpartum pre-eclampsia is limited and there are no preventive treatments. Future research must investigate the pathogenesis of pre-eclampsia, in particular of term and postpartum pre-eclampsia, and evaluate new prognostic tests and treatments in adequately powered clinical trials.

The feasibility of soluble Fms-Like Tyrosine kinase-1 (sFLT-1) and Placental Growth Factor (PlGF) ratio biomarker in predicting preeclampsia and adverse pregnancy outcomes among medium to high risk mothers in Kuala Lumpur, Malaysia

Background

Preeclampsia significantly contributes to maternal and perinatal morbidity and mortality. It is imperative to identify women at risk of developing preeclampsia in the effort to prevent adverse pregnancy outcomes through early intervention. Soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) level changes are noticeable several weeks before the onset of preeclampsia and its related complications. This study evaluated the feasibility of the sFlt-1/PlGF biomarker ratio in predicting preeclampsia and adverse pregnancy outcomes using a single cut-off point of >38.

Methods

This is a prospective cohort study conducted at a single tertiary centre, in an urban setting in Kuala Lumpur, Malaysia, between December 2019 and April 2021. A total of 140 medium to high risk mothers with singleton pregnancies were recruited at ≥20 weeks’ gestation. sFlt-1/PlGF ratio was measured and the participant monitored according to a research algorithm until delivery. The primary outcome measure was incidence of preeclampsia and the secondary outcome measure was incidence of other adverse pregnancy outcomes.

Results

The overall incidence of preeclampsia was 20.7% (29/140). The mean sFlt-1/PlGF ratio was significantly higher in preeclampsia (73.58 ± 93.49) compared to no preeclampsia (13.41 ± 21.63) (p = 0.002). The risk of preeclampsia (adjusted OR 28.996; 95% CI 7.920–106.164; p<0.001) and low Apgar score (adjusted OR 17.387; 95% CI 3.069–98.517; p = 0.028) were significantly higher among women with sFlt-1/PlGF ratio >38 compared with sFLT-1/PlGF ratio ≤38. The area under the receiver-operator characteristic curve (AUC) for a combined approach (maternal clinical characteristics and biomarker) was 86.9% (p<0.001, 95% CI 78.7–95.0) compared with AUC biomarker alone, which was 74.8% (p<0.001, 95% CI 63.3–86.3) in predicting preeclampsia. The test sensitivity(SEN) was 58.6%, specificity (SPEC) 91%,positive predictive value (PPV) 63% and negative predictive value (NPV) 89.3% for prediction of preeclampsia. For predicting a low Apgar score at 5 minutes, the SEN was 84.6%, SPEC 87.4%, PPV 40.7%, and NPV 98.2%; low birth weight with SEN 52.6%,SPEC 86.0%, PPV 37.0%, NPV 92.0%; premature delivery with SEN 48.5%, SPEC 89.5%, PPV 59.3%, NPV 84.7% and NICU admission with SEN 50.0%, SPEC 85.8%, PPV 37.0% and NPV 91.2%.

Conclusions

It is feasible to use single cut-off point of >38 ratio of the biomarkers sFlt-1/PlGF in combination with other parameters (maternal clinical characteristics) in predicting preeclampsia and adverse pregnancy outcomes among medium to high risk mothers without restricting outcome measurement period to 1 and 4 weeks in a single urban tertiary centre in Kuala Lumpur, Malaysia.

Serum Biomarkers of Maternal Morbidity and Adverse Outcome in Severe Pre-Eclampsia

OBJECTIVE

To evaluate the association of maternal serum biomarkers of myocardial damage, oxidative stress and angiogenic imbalance with maternal adverse outcomes in women with severe pre-eclampsia.

METHODS

This was a prospective cohort study, where maternal serum biomarkers were evaluated in women admitted with severe pre-eclampsia to a tertiary care centre between March 2019 and February 2020. Serum markers included brain naturetic peptide (BNP), cardiac troponin-T (cTnT), cystatin-C (cys-C), soluble fms-like tyrosine kinase-1 (sFlt-1), placental growth factor (PlGF), Total Anti-Oxidant status (TAO) and malondialdehyde (MAO). Main outcome measures were adverse maternal outcomes defined as eclampsia, pulmonary oedema, acute kidney injury, placental abruption and HELLP syndrome.

RESULTS

Adverse maternal outcomes occurred in 93(37.2%, 95% CI: 31.2%-43.6%) of the 250 women with severe pre-eclampsia included in the study, including 21 with pulmonary oedema, 25 with acute kidney injury and 36 with eclampsia. BNP levels were higher among women who developed pulmonary oedema (55.4 pg/mL vs 42.0 pg/mL, p = 0.008). TAO levels were higher in women who developed eclampsia (4.6 mM, IQR 3.1-5.7, p < 0.001) and acute kidney injury (4.1 mM, IQR 3.2-6.3, p = 0.002) compared to those who did not develop any complications (2.93 mM, IQR 2.3-4.1).

CONCLUSIONS

Even though the endothelial dysfunction and oxidative stress biomarkers were associated with development of preeclampsia, it may have limited utility in identifying women who might develop adverse outcomes.

Association of endothelial nitric oxide synthase gene variants with preeclampsia

Background

Preeclampsia (PE) is a complex pregnancy hypertensive disorder with multifaceted etiology. The endothelial nitric oxide synthase (eNOS) gene and nitric oxide (NO) levels has been reported to be associated with PE predisposition in various populations. Therefore, present study was designed to investigate the role of NO levels and eNOS gene variants in preeclamptic women in Pakistan.

Methods

A total of 600 women were evaluated, 188 of PE with mild features, 112 of PE with severe features and 300 normotensive pregnant women. NO levels were detected by Greiss reaction method and genotyping following sequencing was conducted for eNOS gene variants. Further insilico studies were performed to get insights into the structural and functional impact of identifies mutation on eNOS protein as well as on protein regulation.

Results

Reduced concentrations of NO were reported in all PE groups (p < 0.05) as compared to controls. The frequency of c.894 T (p.298Asp) and g.-786C alleles were significantly associated with PE. In addition, novel homozygous variant g.2051G > A was also significantly associated with PE when compared to normotensive women. Dynamic simulation studies revealed that Glu298Asp mutation destabilize the protein molecule and decrease the overall stability of eNOS protein. Molecular docking analysis of mutant promoter with transcription factors STAT3 and STAT6 proposed changes in protein regulation upon these reported mutations in upstream region of the gene.

Conclusion

Considering the results of current study, the functional alterations induced by these variants may influence the bioavailability of NO and represents a genetic risk factor for increased susceptibility to PE. However, large studies or meta-analysis are necessary to validate these findings.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12978-021-01213-9.

Preeclampsia (PE) is a complex pregnancy hypertensive disorder with multifaceted etiology characterized by increased hypertension and proteinuria after 20 weeks of gestation. The present study was directed to determine the role of eNOS in susceptibility to PE and the association of c.894G > T (p.(Glu298Asp), intron 4b/4a, g.-786 T > C and other possible variants of eNOS gene with preeclampsia in Pakistani population. Computational analysis of identified variants in the coding and non-coding region of the eNOS gene was also conducted to determine the change in gene regulation and further protein stability. A total of 600 women were evaluated, 188 with mild and 112 with PE with severe features PE with 300 normotensive pregnant women. NO levels and genotyping following sequencing was conducted for eNOS gene variants. Further insilico studies were performed to get insights into the structural and functional impact of identifies mutation on eNOS protein as well as on protein regulation. Data from the current study suggest that there might be other risk variants of the eNOS gene (g.2051G > A and g.1861G > A) and lower levels of serum NO that confers in an increased risk of PE. The detailed computational investigation further confirmed the deformities and changes in protein flexibility upon Glu298Asp. These structural alterations might be associated with preeclampsia. Variants in the promoter region of the eNOS gene further validate the change in gene regulation for the onset of disease. Identification of key structural and functional features in eNOS protein and gene regulatory region might be used for designing specific drugs for therapeutic purpose.

Determination of Urine Protein Levels and Analysis of Differences in Vascular Endothelial Growth Factor Levels between Early Onset and Late Onset Preeclampsia

BACKGROUND: Preeclampsia is a disease with the high mortality rate. Data indicate that 23.5% of maternal deaths due to preeclampsia. Urine protein testing is essential for pregnant women to discover the function of kidney during pregnancy and to identify the presence of preeclampsia, both mild and severe, which it can lead to eclampsia. Preeclampsia based on onset can also be detected by examining serum biomarkers of Vascular Endothelial Growth Factor (VEGF). AIM: The aim of this study was to overview the urine protein levels and analyzed the differences serum VEGF levels between the early and late onset of preeclampsia. MATERIALS AND METHODS: This study used design of the cross sectional comparative study in RSUP DR. M Djamil Padang, Pariaman Hospital, Aisiyah Pariaman Hospital, and Padang Pariaman Regional Hospital for 2 years. The population in this study consisted of patients with early and late onset preeclampsia who went to the study site during that time and met the inclusion criteria. Sampling with consecutive sampling consisted of 28 people per group. RESULTS: The results revealed that the number of patients who had urine protein levels with a value of 2+ at the early onset was 14 and at the late onset was 12, meanwhile for patients with a urine protein content value of 3+ at the early onset it was 14 and at the late onset was 10.For the category urine protein with a value of 4+ amounted to 6 people only in the late onset group. The results of the normality test showed that the mean value of VEGF levels at early onset and late onset was 3.91 pg / ml and 4.3 pg / ml, respectively. Thus, the level of VEGF serum had an abnormal distribution and it led to the T test data could not be tested. So then, the testing was done using a non-parametric test, namely the Mann-Whittney test. The mean levels of VEGF, respectively, based on the Mann-Whittney test for early onset preeclampsia and late onset preeclampsia were 29.75 ng / mL and 30.25 ng / mL. VEGF in early onset preeclampsia is lower than late onset preeclampsia. CONCLUSION: Based on the results obtained, it can be concluded that there was no significant difference in the level of VEGF in early onset preeclampsia and late onset preeclampsia (p = 0.42). Keywords: Preeclampsia, early onset, late onset, urine protein, VEGF

A narrative review on the role of folate-mediated one-carbon metabolism and its associated gene polymorphisms in posing risk to preeclampsia

Preeclampsia (PE) presents a major obstetrical problem for mother and fetus which is characterized by the onset of hypertension and proteinuria in formerly normotensive women. Altered folate-mediated one-carbon metabolism is one of the factors for PE development either due to nutritional insufficiencies such as folate deficiency or polymorphisms in genes that code for the key enzymes of the cycle. Commonly, there are four genes in the cycle whose polymorphisms have been described in relation to PE. These factors could cause elevation of homocysteine; the toxic metabolite, which subsequently leads to the development of PE. Sufficient levels of folate have been considered important during pregnancy and may reduce the risk of development of PE. This review aims at discussing genetic polymorphisms and nutritional deficiencies as probable predisposing factors and suggests considering fetal genotypes, varied ethnicities, and interaction of various other factors involved to render better conclusiveness to the present studies.

Preeclamptic Women Have Decreased Circulating IL-10 (Interleukin-10) Values at the Time of Preeclampsia Diagnosis: Systematic Review and Meta-Analysis

A key immunomodulatory cytokine, IL-10 (interleukin-10), has been shown to be dysregulated in preeclampsia, a pregnancy-specific hypertensive disorder, further characterized by multi-system involvement. However, studies have reported inconsistent findings about circulating IL-10 levels in preeclamptic versus normotensive pregnancies. The aim of the present systematic review and meta-analysis was to assess circulating IL-10 levels in preeclamptic and normotensive pregnancies at 2 time points: before, and at the time of preeclampsia diagnosis. PubMED, EMBASE, and Web of Science databases were searched to include all published studies examining circulating IL-10 levels in preeclamptic and normotensive pregnancies. Differences in IL-10 levels were evaluated by standardized mean differences. Of 876 abstracts screened, 56 studies were included in the meta-analysis. Circulating IL-10 levels were not different before the time of active disease (standardized mean differences, -0.01 [95% CI, -0.11 to 0.08]; P=0.76). At the time of active disease, women with preeclampsia (n=1599) had significantly lower IL-10 levels compared with normotensive controls (n=1998; standardized mean differences, -0.79 [95% CI, -1.22 to -0.35]; P=0.0004). IL-10 levels were lower in both early/severe and late/mild forms of preeclampsia. Subgroup analysis revealed that IL-10 measurement methodology (ELISA or multiplex bead array) and the sample type (plasma or serum) significantly influenced the observed differences, with the use of sera paired with ELISA technology providing the best distinction in IL-10 levels between preeclamptic and normotensive pregnancies. These findings support the role of decreased IL-10 levels in the pathophysiology of preeclampsia. Future studies should address the therapeutic potential of IL-10 in preeclampsia.

Mechanisms of vascular dysfunction in the interleukin-10-deficient murine model of preeclampsia indicate nitric oxide dysregulation

Preeclampsia is a pregnancy-specific hypertensive disorder characterized by proteinuria, and vascular injury in the second half of pregnancy. We hypothesized that endothelium-dependent vascular dysfunction is present in a murine model of preeclampsia based on administration of human preeclamptic sera to interleukin-10-/- mice and studied mechanisms that underlie vascular injury. Pregnant wild type and IL-10-/- mice were injected with either normotensive or severe preeclamptic patient sera (sPE) during gestation. A preeclampsia-like phenotype was confirmed by blood pressure measurements; assessment of albuminuria; measurement of angiogenic factors; demonstration of foot process effacement and endotheliosis in kidney sections; and by accumulation of glycogen in placentas from IL-10-/- mice injected with sPE sera (IL-10-/-sPE). Vasomotor function of isolated aortas was assessed. The IL-10-/-sPE murine model demonstrated significantly augmented aortic contractions to phenylephrine and both impaired endothelium-dependent and, to a lesser extent, endothelium-independent relaxation compared to wild type normotensive mice. Treatment of isolated aortas with indomethacin, a cyclooxygenase inhibitor, improved, but failed to normalize contraction to phenylephrine to that of wild type normotensive mice, suggesting the additional contribution from nitric oxide downregulation and effects of indomethacin-resistant vasoconstricting factors. In contrast, indomethacin normalized relaxation of aortas derived from IL-10-/-sPE mice. Thus, our results identify the role of IL-10 deficiency in dysregulation of the cyclooxygenase pathway and vascular dysfunction in the IL-10-/-sPE murine model of preeclampsia and point towards a possible contribution of nitric oxide dysregulation. These compounds and related mechanisms may serve both as diagnostic markers and therapeutic targets for preventive and treatment strategies in preeclampsia.

Syncytiotrophoblast extracellular microvesicle profiles in maternal circulation for noninvasive diagnosis of preeclampsia

Preeclampsia is the most common placental pathology in pregnant females, with increased morbidity and mortality incurred on the mother and the fetus. There is a need for improved biomarkers for diagnosis and monitoring of this condition. Placental syncytiotrophoblasts at the maternal-fetal interface release nanoparticles, including extracellular microvesicles, into the maternal blood during pregnancy. Syncytiotrophoblast extracellular microvesicles (STEVs) are being studied for their diagnostic potential and for their potential physiologic role in preeclampsia. We hypothesized that STEV profiles in maternal circulation would be altered under conditions of preeclampsia compared to normal pregnancy. Extracellular vesicles (EVs) released by BeWo cells in vitro showed high expression of syncytin-1, but no plac1 expression, demonstrating that trophoblast cell EVs express syncytin-1 on their surface. Placental alkaline phosphatase also showed high expression on BeWo EVs, but due to concern for cross reactivity to highly prevalent isoforms of intestinal and bone alkaline phosphatase, we utilized syncytin-1 as a marker for STEVs. In vivo, syncytin-1 protein expression was confirmed in maternal plasma EVs from Control and Preeclampsia subjects by Western blot, and overall, lower expression was noted in samples from patients with preeclampsia (n = 8). By nanoparticle analysis, EV profiles from Control and Preeclampsia groups showed similar total plasma EV quantities (p = 0.313) and size distribution (p = 0.415), but STEV quantitative signal, marked by syncytin-1 specific EVs, was significantly decreased in the Preeclampsia group (p = 2.8 × 10⁻¹¹). Receiver operating characteristic curve demonstrated that STEV signal threshold cut-off of <0.316 was 95.2% sensitive and 95.6% specific for diagnosis of preeclampsia in this cohort (area under curve = 0.975 ± 0.020). In conclusion, we report that the syncytin-1 expressing EV profiles in maternal plasma might serve as a placental tissue specific biomarker for preeclampsia.

An Insight into the Angiogenic and Lymphatic Interplay in Pre-eclampsia Comorbid with HIV Infection

PURPOSE OF REVIEW

To provide insight on the imbalance of angiogenic and lymphangiogenic factors in pre-eclampsia, as well as highlight polymorphism in genes related to angiogenesis and lymphangiogenesis.

RECENT FINDINGS

The pregnancy-specific disorder pre-eclampsia is diagnosed by the presence of hypertension with/without proteinuria, after 20 weeks of gestation. The pathogenesis of pre-eclampsia remains ambiguous, but research over the years has identified an imbalance in maternal and foetal factors. Familial predisposition and gene variation are also linked to pre-eclampsia development. The sFlt-1/PIGF ratio has attracted great attention over the years; more recently several researchers have reported that a sFlt-1/PIGF ratio of ≤ 38 can be used to predict short-term absence of pre-eclampsia. This ratio has the potential to prevent adverse pregnancy outcomes and reduce healthcare costs significantly. Genome-wide studies have additionally identified variation in the foetal gene near Flt-1. The development of preeclampsia is not limited to the maternal interface, but foetal involvement as well as genetic interplay is associated with the disorder.

Placental endothelial nitric oxide synthase expression and role of oxidative stress in susceptibility to preeclampsia in Pakistani women

BACKGROUND

Preeclampsia (PE): a hypertensive disorder of pregnancy characterized by de novo development of concurrent hypertension and proteinuria. The prevailing theory determined that PE starts from the placenta and ends in the maternal endothelium. Role of endothelial dysfunction in the onset of PE has been reported in different populations. Therefore, present study was designed to investigate the localization and expression of endothelial nitric oxide synthase (eNOS) and role of oxidative stress markers in preeclamptic Pakistani women.

METHODS

A total of 400 blood samples (PE = 200, controls = 200) and 100 placental tissues (PE = 50, controls = 50) were recruited from pregnant women. Reactive oxygen species (ROS), thiobarbituric acid reactive substances (TBARS), superoxide dismutase (SOD), catalase (CAT), and guaiacol peroxidase (POD) levels were analyzed through spectrophotometer. Immunohistochemistry and quantitative real-time polymerase chain reaction (qRT-PCR) were carried out to estimate the localization and expression of eNOS in the placentas of PE patients and healthy pregnant women.

RESULTS

Significantly increased levels of POD (0.01), TBARS (0.04), and ROS (p ≤ .001) were determined in preeclamptic women while, nonsignificant change in SOD and CAT was observed in both groups. Reduced eNOS immunoreactivity (p ≤ .001) and mRNA abundance (p ≤ .001) was observed in preeclamptic group as compared to control group.

CONCLUSION

Considering the results of current study, it is concluded that decreased eNOS expression and oxidative stress could play a role in the pathology of PE seen both in placenta and ultimately in maternal endothelium. However, large studies are necessary to validate these findings to prevent maternal and neonatal morbidity and mortality in Pakistani population.

The Association Between GFR Evaluated by Serum Cystatin C and Proteinuria During Pregnancy

Introduction

Physiological changes in pregnancy result in increased cardiac output and renal blood flow, with a consequential increase in proteinuria. Data from studies of the relationship between proteinuria caused by isolated proteinuria and glomerular filtration rate (GFR) are still limited. The objective of this study was to investigate the effects of isolated proteinuria on the cystatin C–based GFR in the third trimester of pregnancy.

Methods

Data were collected from pregnant women in their third trimester whose serum creatinine levels were normal. The GFR of each participant was measured using serum cystatin C levels, and proteinuria was measured using urine protein–creatinine ratios. The participants were divided into 3 groups according to their level of proteinuria: normal (<150 mg/d), physiological (150–300 mg/d), and gestational (>300 mg/d). Changes in GFR were recorded for each group.

Results

The study included 89 participants, of whom 66.3% had levels of proteinuria that did not differ from that of the normal population (<150 mg/d). The incidence of physiological and gestational proteinuria was 21.4% and 12.4%, respectively. The results demonstrate that proteinuria >101.50 mg/d was significantly associated with declined estimated glomerular filtration rate (eGFR) (r = –0.34, P = 0.01). The analysis found that proteinuria >491.27 mg/d led to a risk of GFR <90 ml/min with an odds ratio of 12.69, P = 0.02 when adjusted for systolic blood pressure (SBP), diastolic blood pressure (DBP), and body mass index.

Conclusion

This study suggests that the term “physiological proteinuria” is a misnomer. When used in the traditional manner, creatinine level has inadequate sensitivity to estimate GFR in pregnant women. We found that there is a significant decline in GFR when urine protein > 101.5 mg/d, which could be an early biomarker for renal pathology rather than pregnancy physiology, suggesting that further workup and precaution is required.

Increased circulating trimethylamine N-oxide plays a contributory role in the development of endothelial dysfunction and hypertension in the RUPP rat model of preeclampsia

OBJECTIVE

We examined whether trimethylamine-N-oxide (TMAO) plays a role in endothelial dysfunction and hypertension in the reduced uterine perfusion pressure (RUPP) rat model of preeclampsia (PE).  Methods: Normal pregnant rats and RUPP rats were treated without or with 3,3-Dimethyl-1-butanol (DMB, a TMAO inhibitor) from gestational day 14.  Results: On day 19 of gestation, RUPP rats had higher plasma TMAO, impaired vasodilation and hypertension, decreased interleukin (IL)-10, increased superoxide production and proinflammatory cytokines in the aorta. All of which were reversed by DMD.  Conclusion: Increased circulating TMAO downregulates IL-10 and promotes vascular inflammation and oxidative stress, contributing to endothelial dysfunction and hypertension in PE.

A Comparative Study of Fractionated Versus Single Dose Injection for Spinal Anesthesia During Cesarean Section in Patients with Pregnancy-Induced Hypertension

Background

Local anesthetics for spinal anesthesia in one-single injection are known to induce more severe hypotension than a fractionated dose in healthy obstetric patients. Hypotension in obstetric patients with pregnancy-induced hypertension, including preeclampsia, during spinal anesthesia, could compromise fetal well-being.

Objectives

This study aimed to compare the mean arterial pressure (MAP), the total dose of ephedrine required, and level of sensory blockade between the fractionated-dose and single-dose spinal anesthesia injection in obstetric patients with pregnancy-induced hypertension who underwent a cesarean section.

Methods

This single-blind randomized clinical trial was conducted from January to April 2018 after being approved by the Research Ethics Committee of Universitas Indonesia (No. 1174/UN2.F1/ETIK/2017) and recorded at ClinicalTrials.gov (NCT03693638). After obtaining informed consent, 42 parturients with hypertension in pregnancy (gestational hypertension or preeclampsia), ASA II-III, aged 18 - 40 years, and BMI of 18.5 - 35 kg/m² with singleton pregnancy, who were planned for spinal anesthesia for emergency or semi-emergency cesarean section with hyperbaric bupivacaine 0.5% (Marcaine^TM, Hospira) and fentanyl, were included in this study. All subjects were randomly divided into two groups including fractionated-dose (FD) and single-dose (SD).

Results

There was no significant difference between the two groups in MAP in the first 15 minutes after anesthesia (P > 0.05) and median total dose of ephedrine required (10 (0 - 25) mg in the FD group vs. 15 (0 - 30) mg in the SD group, P = 0.30). However, in the FD group, MAP tended to be higher in the first three minutes compared to the SD group. The level of sensory blockade was mostly at T4, which was not significantly different between the groups (52.4% in FD vs. 42.9% in SD, P = 0.59).

Conclusions

In obstetric patients with pregnancy-induced hypertension who underwent a cesarean section, the mean arterial pressure after spinal anesthesia was not significantly different between the fractionated dose of spinal anesthesia injection and single-dose injection. Total ephedrine required and levels of sensory blockade were not significantly different between the groups.

Maternal pregnancy-induced hypertension increases subsequent neonatal necrotizing enterocolitis risk: A nationwide population-based retrospective cohort study in Taiwan

The utero-placental ischemia induced by pregnancy-induced hypertension (PIH) could lead to fetal hypoxia and proinflammatory cytokine release, which are associated with the development of neonatal necrotizing enterocolitis (NEC). However, a few studies have investigated the relationship between PIH and neonatal NEC and have produced controversial results. Therefore, we attempted to assess the relationship between PIH and the subsequent neonatal NEC risk and identify predictive risk factors.Patients with newly diagnosed PIH were recruited from the Taiwan National Health Insurance Research Database (NHIRD). For each participant, 4 age- and delivery-year-matched participants without PIH were randomly selected. A multivariable logistic regression was performed for the identification of the predictive risk factors for neonatal NEC.Among the 23.3 million individuals registered in the NHIRD, 29,013 patients with PIH and 116,052 matched controls were identified. For the multivariable analysis, maternal PIH was associated with an increased risk of subsequent neonatal NEC development (odds ratio [OR] 1.86, 95% confidence interval [CI] 1.08-3.21, P = .026). Furthermore, single parity (OR 2.06, 95% CI 1.12-3.77, P = .019), preterm birth (OR 5.97, 95% CI 3.49-10.20, P < .001), multiple gestations (OR 2.25, 95% CI 1.22-4.14, P = .010), and intrauterine growth restriction (IUGR) (OR 3.59, 95% CI 2.06-6.24, P < .001) were independent risk factors for the development of subsequent neonatal NEC.Maternal PIH increases the risk for developing neonatal NEC. Furthermore, primiparity, preterm birth, multiple gestations, and IUGR were independent risk factors for neonatal NEC.

Preeclampsia: Novel Mechanisms and Potential Therapeutic Approaches

Preeclampsia is a serious complication of pregnancy where it affects 5–8% of all pregnancies. It increases the morbidity and mortality of both the fetus and pregnant woman, especially in developing countries. It deleteriously affects several vital organs, including the kidneys, liver, brain, and lung. Although, the pathogenesis of preeclampsia has not yet been fully understood, growing evidence suggests that aberrations in the angiogenic factors levels and coagulopathy are responsible for the clinical manifestations of the disease. The common nominator of tissue damage of all these target organs is endothelial injury, which impedes their normal function. At the renal level, glomerular endothelial injury leads to the development of maternal proteinuria. Actually, peripheral vasoconstriction secondary to maternal systemic inflammation and endothelial cell activation is sufficient for the development of preeclampsia-induced hypertension. Similarly, preeclampsia can cause hepatic and neurologic dysfunction due to vascular damage and/or hypertension. Obviously, preeclampsia adversely affects various organs, however it is not yet clear whether pre-eclampsia per se adversely affects various organs or whether it exposes underlying genetic predispositions to cardiovascular disease that manifest in later life. The current review summarizes recent development in the pathogenesis of preeclampsia with special focus on novel diagnostic biomarkers and their relevance to potential therapeutic options for this disease state. Specifically, the review highlights the renal manifestations of the disease with emphasis on the involvement of angiogenic factors in vascular injury and on how restoration of the angiogenic balance affects renal and cardiovascular outcome of Preeclamptic women.

Nitric Oxide and Pre-Eclampsia: A Comparative Study in Ghana

BACKGROUND

Preeclampsia is one of the commonest aetiologies of foetal and maternal mortality and morbidity. Though common, the aetiology of preeclampsia has remained unknown with several inconclusive theories surrounding the disease. Recent studies have implicated vascular endothelial dysfunction and possibly nitric oxide in preeclampsia.

AIM

To compare plasma nitric oxide levels in pre-eclampsia and healthy pregnant women in a large tertiary hospital in Ghana.

METHODS

This was a case-control study conducted among pre-eclampsia and healthy pregnant women in Korle-Bu Teaching Hospital over a four-month period. Thirty (30) pre-eclamptic and 30 healthy pregnant women aged 18-35 years with over 30 weeks' gestation were consecutively recruited into the study after obtaining informed consent. Plasma nitric oxide levels were determined using the Griess Reagent system. Data were analysed using Statistical Package for the Social Sciences (SPSS) software version 20.0 and results were compared using the independent t-test. A P-value of ≤ 0.05 was considered statistically significant.

RESULTS

The parity and body mass index (BMI) of the participants were similar. There was a significant difference in the blood pressure of the pre-eclamptic compared to healthy pregnant women. There was no statistically significant difference (P-value = 0.160) in the plasma levels of nitric oxide in pre-eclamptic (Mean = 1178.78; SD = 89.70 nM) compared to healthy pregnant women (Mean = 1365.43; SD = 95.46 nM).

CONCLUSION

Plasma nitric oxide levels may not play a significant role in the aetiology of pre-eclampsia.

Placental ischemia-stimulated T-helper 17 cells induce preeclampsia-associated cytolytic natural killer cells during pregnancy

Previous studies have demonstrated that T-helper 17 (T_H17) cells and cytolytic natural killer (cNK) cells are increased in women with preeclampsia. In this study we investigated the role of placental ischemia-stimulated T_H17 cells in induction of cNK cells in pregnancy. We further assessed the role of T_H17 cell-mediated oxidative stress in facilitation of cNK cell activation in pregnancy by treating rats with the SOD mimetic tempol. CD4⁺/CD25^- cells were isolated from reduced uterine perfusion pressure (RUPP) rats and differentiated into T_H17 cells in vitro. On day 12 of gestation ( GD12), 1 × 10⁶ placental ischemia-stimulated T_H17 cells were injected into normal pregnant (NP) rats (NP + RUPP T_H17 rats), and a subset of rats were treated with tempol (30 mg·kg^-1·day^-1) from GD12 to GD19 (NP + RUPP T_H17 + tempol rats). On GD19, cNK cells, mean arterial pressure, fetal weight, and cNK cell-associated cytokines and proteins were measured. Placental cNK cells were 2.9 ± 1, 14.9 ± 4, and 2.8 ± 1.0% gated in NP, NP + RUPP T_H17, and NP + RUPP T_H17 + tempol rats, respectively. Mean arterial pressure increased from 96 ± 5 mmHg in NP rats to 118 ± 2 mmHg in NP + RUPP T_H17 rats and was 102 ± 3 mmHg in NP + RUPP T_H17 + tempol rats. Fetal weight was 2.37 ± 0.04, 1.95 ± 0.14, and 2.3 ± 0.05 g in NP, NP + RUPP T_H17, and NP + RUPP T_H17 + tempol rats, respectively. Placental IFNγ increased from 1.1 ± 0.6 pg/mg in NP rats to 3.9 ± 0.6 pg/mg in NP + RUPP T_H17 rats. Placental perforin increased from 0.18 ± 0.18 pg/mg in NP rats to 2.4 ± 0.6 pg/mg in NP + RUPP T_H17 rats. Placental levels of granzymes A and B followed a similar pattern. Treatment with tempol did not lower placental cNK cytokines or proteins. The results of the present study identify T_H17 cells as a mediator of aberrant NK cell activation that is associated with preeclampsia.

The Role of Interleukin-10 in the Pathophysiology of Preeclampsia

PURPOSE OF REVIEW

The pathophysiology of preeclampsia is complex and not entirely understood. A key feature in preeclampsia development is an immunological imbalance that shifts the maternal immune response from one of tolerance towards one promoting chronic inflammation and endothelial dysfunction. As a key regulator of immunity, IL-10 not only has immunomodulatory activity, but also directly benefits vasculature and promotes successful cellular interactions at the maternal-fetal interface. Here we focus on the mechanisms by which the dysregulation of IL-10 may contribute to the pathophysiology of preeclampsia.

RECENT FINDINGS

Dysregulation of IL-10 has been demonstrated in various animal models of preeclampsia. Decreased IL-10 production in both placenta and peripheral blood mononuclear cells has been reported in human studies, but with inconsistent results. The significance of IL-10 in preeclampsia has shifted from a key biomarker to one with therapeutic potential. As such, a better understanding of the role of this cytokine in the pathophysiology of preeclampsia is of paramount importance.

The blocking of aquaporin-3 (AQP3) impairs extravillous trophoblast cell migration

Several aquaporins (AQPs) are expressed in extravillous (EVT) and villous trophoblast cells. Among them, AQP3 is the most abundant AQP expressed in chorionic villi samples from first trimester, followed by AQP1 and AQP9. Although AQP3 expression persists in term placentas, it is significantly decreased in placentas from preeclamptic pregnancies. AQP3 is involved in the migration of different cell types, however its role in human placenta is still unknown. Here, we evaluated the role of AQP3 in the migration of EVT cells during early gestation. Our results showed that Swan 71 cells expressed AQP1, AQP3 and AQP9 but only the blocking of AQP3 by CuSO₄ or the silencing of its expression by siRNA significantly attenuates EVT cell migration. Our work provides evidence that AQP3 is required for EVT cell migration and suggests that an altered expression of placental AQP3 may produce failures in placentation such as in preeclampsia.

Preeclampsia: From Inflammation to Immunoregulation

Preeclampsia (PE) affects 5% to 7% of pregnant women each year worldwide, accounts for up to 18% of maternal deaths in the United States each year, and is the number 1 cause of premature births. Preeclampsia is associated with hypertension after the 20th week of gestation with or without proteinuria, in conjunction with fetal growth restriction, maternal endothelial dysfunction, and chronic immune activation. The mechanisms leading to the development of PE are unclear. However, it is thought that shallow trophoblast invasion and insufficient remodeling of uterine spiral arteries result in placental ischemia. Consequently, an immune imbalance characterized by increases in proinflammatory CD4⁺ T cells and cytokines along with decreases in regulatory T cells and anti-inflammatory cytokines occurs. This imbalance leads to chronic inflammation and ensuing oxidative stress, proinflammatory cytokines, and autoantibodies. Studies performed in our laboratories, using the Reduced Uterine Perfusion Pressure (RUPP) rat model of placental ischemia, have demonstrated a role for this immune imbalance to mediate PE pathophysiology and identified potential mechanisms of immunoregulation that may be of benefit in the treatment of PE. Therefore, the purpose of this commentary is to review studies demonstrating the positive effects of immunoregulatory factors in the RUPP rat model of PE. Restoration of the immune balance in PE may be a potential strategy for the development of therapeutic interventions that could improve maternal and fetal outcomes associated with this maternal syndrome.

Continued Investigation Into 17-OHPC: Results From the Preclinical RUPP Rat Model of Preeclampsia

Preeclampsia is characterized by elevated TNF-α (tumor necrosis factor-α), antiangiogenic factors, such as sFlt-1 (soluble vascular endothelial growth factor receptor 1), increased uterine artery resistance index, and decreased of NO during pregnancy. Previously we showed that 17-hydroxyprogesterone caproate (17-OHPC) administered into reduced uterine perfusion pressure (RUPP) rats on day 18 of gestation improved hypertension without improving pup weight. We hypothesized that earlier administration of 17-OHPC on day 15 of gestation could improve pathophysiology of preeclampsia and fetal outcomes in response to placental ischemia. Carotid catheters were inserted on day 18, and mean arterial blood pressure and samples were collected on day 19. Mean arterial blood pressure in normal pregnant rats was 102±2, 105±2 in normal pregnant+day 15 of gestation (GD15) 17-OHPC, 127±2 in RUPP and 112±1 mm Hg in RUPP+GD15 17-OHPC, P<0.05. Pup weight and litter size were improved from 1.9±0.05, 10.1±1.4 in RUPP to 2.1±0.07 g and 13.2±0.6 in RUPP+GD15 17-OHPC, P<0.05. Uterine artery resistance index was 0.8±0.03 in RUPP, which was decreased to 0.6±0.04 in RUPP+GD15 17-OHPC, P<0.05. Plasma TNF-α levels were 164±34 in RUPP and blunted to 29±9 pg/mL in RUPP+GD15 17-OHPC, P<0.05. Plasma nitrate-nitrite levels were 10.8±2.3 in RUPP rats and significantly increased to 25.5±5.2 µmol/L in RUPP+GD15 17-OHPC, P<0.05. sFlt-1 levels were 386±141 in RUPP rats, which were reduced to 110.2±11 in RUPP+17-OHPC, P<0.05. These data indicate that GD15 17-OHPC improves pathophysiology in RUPP rats, possibly via improving sFlt-1 reduced NO during pregnancy.

CUL4A enhances human trophoblast migration and is associated with pre-eclampsia

We previously found that cullin 4A (CUL4A) is able to promote trophoblast invasion. However, the role of CUL4A in other trophoblast behavior such as migration and the association with pregnancy disorder remains unclear. In this study, Immunostaining revealed that CUL4A was relatively lowly expressed in placentas from pre-eclampsia patients compared with the normal controls. Spiral arteries and inadequate trophoblast migration remodeling result in poor placental perfusion, which mediated maternal injury and may lead to pre-eclampsia. To confirm CUL4A's function on trophoblast migration, we employed human villous explants culture and trophoblast cell line HTR-8/SVneo migration and invasion assay. According to our data, knocking-down CUL4A expression inhibited villous explant's outgrowth significantly in vitro, and down-regulated migration of HTR8/SVneo cells (P<0.01). This effect might be due to reduced matrix metalloproteinases activities, whereas the apoptosis and proliferation of trophoblast cells were not affected. Moreover, CUL4A siRNA increased the levels of both tissue inhibitors of MMPs (TIMP)-1 and -2 significantly. These results suggested that CUL4A may play an essential role in trophoblast cells' migration and dysregulation of CUL4A may be associated with pre-eclampsia.

Impact of Galectin-1 on Trophoblast Stem Cell Differentiation and Invasion in In Vitro Implantation Model

Trophoblast stem cells (TSCs) differentiate in an orderly manner, which plays an important role in the process of embryo implantation, placentation, and early pregnancy maintenance. At the maternal-fetal interface, the dialogue is crucial between trophoblast cells and endometrial epithelial cells. Previous studies suggested that galectin-1 (Gal-1) may play an important role in placental development. In this study, we used Ishikawa (IK) cells-TSC coculture model to simulate the maternal-fetal interface and induce the differentiation of TSCs by differentiation media. The messenger RNA level of each cell type markers, fusion markers, and Gal-1 was detected by quantitative reverse transcription polymerase chain reaction during the differentiation of TSCs. Wound healing and transwell invasion assays were used to detect the migration and invasion ability in each group. We found that coculture with IK cells or conditioned media from IK cells could promote the differentiation and invasion of TSCs and increase Gal-1 expression in TSCs. Furthermore, recombinant Gal-1 could also promote the differentiation and invasion of TSCs, suggesting that some of IK cells secretion increase the expression of Gal-1 in TSCs during implantation, which then induced trophoblast differentiation and invasion in vitro. These findings provide significant insights into the biology of embryo-maternal interactions with the importance of Gal-1 in TSCs for the successful establishment and maintenance of pregnancy.

Genetic variants in 3'-UTRs of MTHFR in the pregnancies complicated with preeclampsia and bioinformatics analysis

Preeclampsia (PE) as a pregnancy-specific disorder is the major cause of mortality and morbidity of mothers and fetuses. This study attempts to investigate the possible association between the 2572C>A (rs4846049) and 4869C>G (rs1537514) polymorphisms in the 3'- untranslated region of MTHFR gene and the risk of PE. A total of 198 patients diagnosed with PE and 171 unrelated, age matched healthy pregnant women, were recruited for this case-control study. The MTHFR 2572C>A and 4869C>G genotyping was performed by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The CG genotype of MTHFR 4869C>G was associated with decreased risk of PE, and this genotype was found to be a protective factor for PE susceptibility. There was no significant difference in the genotypes of MTHFR 2572C>A polymorphism between PE patients and control group. The frequency of combined AC/CG genotypes of MTHFR 2572C>A and 4869C>G polymorphisms were less frequent in PE patients and were associated with a lower risk of PE. The C-G and A-G haplotypes of MTHFR 2572C>A and 4869C>G polymorphisms were significantly lower in PE patients. In conclusion, the CG genotype of MTHFR 4869C>G polymorphism was associated with a lower risk of PE. No association was found between MTHFR 2572C>A polymorphism and PE.

Maternal/fetal eNOS-Glu298Asp genotypes and their influence on the severity, prognosis, and lipid profile of preeclampsia

OBJECTIVES

To analyze the contribution of maternal eNOS-Glu298Asp genotypes and also the association with fetal genotypes to the development of preeclampsia, prognosis, and maternal dyslipidemia.

METHODS

Sixty-nine pairs of preeclamptic mothers/newborns and 94 pairs of normotensive mothers/newborns were genotyped for eNOS-Glu298Asp using PCR-RFLP methods.

RESULTS

Women carriers of at least one Asp298 allele had a 1.53-fold (p = NS), 1.88-fold (p = NS), and 2.08-fold (p = .05), respectively, increased risk to develop PIH, mild, or severe preeclampsia. If both the mother and the newborn were carriers of the Asp298 allele, the risk for preeclampsia was 5.09-fold higher (p < .001). Preeclamptic women with severe preeclampsia had significantly higher cholesterol (mg/dl, 287.23 ± 43.01 versus 235.36 ± 45.01, p = .02) and LDL (mg/dl, 194.9 ± 42.8 versus 144.98 ± 54.84, p = .04) levels and lower HDL levels (mg/dl, 32.12 ± 5.48 versus 57.84 ± 20.59, p = .02) compared to noncarriers. Also, higher LDL levels (mg/dl, 188.76 ± 46.61 versus 136.75 ± 41.85, p = .03) and lower HDL levels (mg/dl, 32.8 ± 5.64 versus 61.06 ± 22.45, p = .02) were found in preeclamptic women with severe preeclampsia whose newborns were carriers of the Asp298 allele.

CONCLUSIONS

The eNOS-Glu298Asp variant (in mothers and newborns) in association with dyslipidemia could affect bioavailability of NO and could represent an increased risk for preeclampsia.

Endothelial dysfunction in the pathogenesis of pre-eclampsia in Ghanaian women

BACKGROUND

Pre-eclampsia (PE) remains a disease of theories despite extensive research into its etiology. Alteration in the production of vascular endothelial growth factor (VEGF), a biomarker of endothelial dysfunction, is associated with pre-eclampsia although conflicting reports have been reported. The aim of the study was to determine and compare maternal serum levels of VEGF among pre-eclamptics, normotensive non pregnant and pregnant women. This was a cross-sectional study involving 100 women with pre-eclampsia, 102 women with normotensive pregnancy and 75 normotensives who were not pregnant. The study was carried out at Korle Bu Teaching Hospital (KBTH) from April to June in 2011. Basic socio-demographic and obstetric data were obtained by means of structured questionnaire. Following venesection, about 5mls of blood was sampled from the participants for the various tests. Enzyme Linked Immunosorbent Assay was used to determine the maternal serum levels of free VEGF. Data analysis was performed using SPSS version 20.

RESULTS

Significant reduction in median serum levels of free VEGF was seen in both, normal pregnant [84.06 pg/ml (IQR: 78.90-99.67)] and pre-eclamptic women [4.71 pg/ml, (IQR: 3.41-7.93)] compared to the non-pregnant (395.85 pg/ml, IQR 234.93-625) with p < 0.001; the reduction was far greater in the pre-eclamptic group compared to that of normotensive pregnant group (p < 0.001). Early-onset pre-eclampsia had significantly more severe reduction in free VEGF levels (3.89, IQR: 2.60-5.67 pg/ml) compared to that of late onset PE (5.23, IQR: 3.78-16.97 pg/ml) with p<0.001 indicating a severer endothelial damage in former.

CONCLUSIONS

Endothelial dysfunction contributes significantly to the pathogenesis of pre-eclampsia as demonstrated by profound decrease in maternal serum VEGF levels in PE compared to normotensive pregnancy and non-pregnancy state. The pathophysiology of early-onset pre-eclampsia may be partly explained by marked reduction in free serum VEGF levels with resultant severe endothelial dysfunction.

Reduced uterine perfusion pressure T-helper 17 cells cause pathophysiology associated with preeclampsia during pregnancy

Preeclampsia is associated with chronic inflammation and an imbalance among T-helper cell subtypes with an increase in T-helper 17 (T_H17) cells. The objective of this study was to determine a role for T_H17s, from the reduced uterine perfusion pressure (RUPP) rat model of preeclampsia, in the etiology of hypertension and chronic inflammation during pregnancy. CD4⁺/CD25^- T cells were isolated from rat spleens, cultured in T_H17 media, and were verified as T_H17s via flow cytometry. On day 12 of gestation, 1×10⁶ T_H17 cells from RUPP rats were adoptively transferred into NP rats, carotid catheters were inserted on day 18, and on day 19, mean arterial pressure (MAP) was recorded, serum and plasma were collected, and oxidative stress and production of agonistic autoantibodies to the ANG II type I receptor (AT₁-AA) were analyzed. MAP increased from 100.3 ± 1.7 mmHg in normal pregnant (NP; n = 17) to 124.8 ± 2.1 mmHg in RUPP (n = 22; P < 0.0001) and to 110.8 ± 2.8 mmHg in NP+RUPP T_H17 (n = 11). Pup weights in NP+RUPP T_H17s were decreased to 1.92 ± 0.09 g from 2.39 ± 0.14 in NP rats (P < 0.01). AT₁-AA significantly increased from 0.1 ± 0.2 beats/min in NP to 15.6 ± 0.7 beats/min in NP+RUPP T_H17s. IL-6 was 22.3 ± 5.7 pg/ml in NP and increased to 60.45 ± 13.8 pg/ml in RUPP (P < 0.05) and 75.9 ± 6.8 pg/ml in NP+RUPP T_H17 rats (P < 0.01). Placental and renal oxidative stress were 238 ± 27.5 and 411 ± 129.9 relative light units·min^-1·mg^-1 in NP and 339 ± 104.6 and 833 ± 331.1 relative light units·min^-1·mg^-1 in NP+RUPP T_H17, respectively. In conclusion, RUPP T_H17 cells induced intrauterine growth restriction and increased blood pressure, AT₁-AA, IL-6, and tissue oxidative stress when transferred to NP rats, indicating a role for autoimmune associated T_H17 cells, to cause much of the pathophysiology associated with preeclampsia.

Prenatal Clinical Assessment of NT-proBNP as a Diagnostic Tool for Preeclampsia, Gestational Hypertension and Gestational Diabetes Mellitus

Common complications of pregnancy include preeclampsia (PE), gestational hypertension (GH) and gestational diabetes mellitus (GDM). Hypertensive disorders (PE/GH) and GDM may result in greater maternal, fetal and neonatal morbidity and mortality. Women with PE/GH, one of the most common causes of heart burden in an obstetrical setting, present with elevated serum levels of BNP and NT-proBNP. The aim of this study was to shed more light on the role of NT-proBNP in pathophysiology of PE, GH and GDM. The study included 156 pregnant women with singleton pregnancies. A total of 26 women developed arterial hypertension during pregnancy, 14 were diagnosed with PE, and GDM was detected in 81 patients. The control group included 35 women with uncomplicated pregnancies, normal arterial blood pressure and normal glucose concentrations. Patients with GH presented with significantly higher serum concentrations of NT-proBNPthan normotensive women (65.5 vs. 37.4 pg/ml; p = 0.0136). Serum levels of NT-proBNP in patients with PE were the highest of all the analyzed subsets, being significantly higher than in women without this condition (89.00 vs. 37.4pg/ml,p = 0,0136). However, women with and without GDM did not differ significantly in terms of their serum NT-proBNPconcentrations. Serum NT-proBNP (pg/ml) (p = 0.0001) and BMI (p<0.0001) turned out to be independent predictors of GH on multivariate logistic regression analysis.Moreover, serum NT-proBNP (pg/ml) was identified as an independent indicator of PE (p = 0.0016). A significant inverse correlation was found between birth weight and maternal serum NT-proBNP concentrations. In our opinion, NT-proBNP can be a useful clinical marker of GH and PE. Determination of NT-proBNP levels may be helpful in identification of patients with PE and GH and in their qualification for intensive treatment; this in turn, may be reflected by better neonatal outcomes.

Lentivirus-mediated PHLDA2 overexpression inhibits trophoblast proliferation, migration and invasion, and induces apoptosis

Inadequate trophoblast invasion and increased trophoblast apoptosis cause serious pregnancy complications. Pleckstrin homology-like domain, family A, member 2 (PHLDA2) has been linked to fetal size at birth and growth restriction in a number of studies. However, the impact of PHLDA2 on trophoblast function had not been studied previously, to the best of our knowledge. In the present study, immunofluorescence staining demonstrated that primary trophoblasts isolated from placental villous tissues were positive for cytokeratin 18 (CK18), vimentin and human placental lactogen (hPL). JEG-3 cells and primary trophoblasts were infected with lentivirus overexpressing PHLDA2. RT-qPCR and western blot analysis detected high levels of PHLDA2. A Cell Counting Kit-8 (CCK-8) assay showed that PHLDA2 overexpression inhibited trophoblast proliferation. In addition, PHLDA2 significantly induced apoptosis, as evidenced by Annexin V-FITC/propidium iodide (PI) and Hoechst staining, along with activation of Bax and caspase-3 and also decreased Bcl-2 expression. Further investigation showed that PHLDA2 effectively induced reactive oxygen species (ROS) generation, caused cytochrome c release from the mitochondria into the cytosol and decreased mitochondrial membrane potential. PHLDA2 likely induced apoptosis through the mitochondrial pathway. Wound healing and Transwell assays indicated that PHLDA2 overexpression efficiently suppressed cell migration and invasion. These data suggest that PHLDA2 plays an important role in the occurrence and development of pregnancy complications by promoting trophoblast apoptosis and suppressing cell invasion.

Prognostic Value of Cardiovascular Disease Risk Factors Measured in the First-Trimester on the Severity of Preeclampsia

Recent studies have suggested that preeclampsia and cardiovascular disease may share common mechanisms. The purpose of this prospective nested case-controlled study was to characterize a variety of cardiovascular disease risk factors measured during the first trimester of pregnancy in predicting subsequent outcomes and the severity of preeclampsia.We ascertained the severity of preeclampsia at the onset of the disease, and the presence of intrauterine growth restriction (IUGR). We compared first trimester maternal serum cardiovascular disease risk factors in preeclampsia subjects versus normal pregnancies, early-onset versus late-onset preeclampsia, and preeclampsia with IUGR versus without IUGR. To identify the prognostic value of independent predictors on the severity of preeclampsia, we calculated the area under the receiver operating characteristics curve (AUC) using logistic regression analysis.There were 134 cases of preeclampsia and 150 uncomplicated pregnancies, and preeclampsia cases were classified as early-onset (53 cases) or late-onset (81 cases), or as with IUGR (44 cases) or without IUGR (90 cases). Among the cardiovascular disease risk factors, maternal serum high-sensitive C-reactive protein (hsCRP) and homocysteine were predictors of both early-onset preeclampsia and preeclampsia with IUGR. For the detection of early onset preeclampsia or preeclampsia with IUGR, the AUC for the combination model (0.943 and 0.952, respectively) was significantly higher than with serum hsCRP or serum homocysteine only.Patients with preeclampsia can be subdivided into different severities according to time of onset and fetal weight. Cardiovascular risk factors distinguish a subgroup of these patients.

Reduced Maternal Erythrocyte Long Chain Polyunsaturated Fatty Acids Exist in Early Pregnancy in Preeclampsia

The present prospective study examines proportions of maternal erythrocyte fatty acids across gestation and their association with cord erythrocyte fatty acids in normotensive control (NC) and preeclamptic pregnancies. We hypothesize that maternal fatty acid status in early pregnancy influences fetal fatty acid stores in preeclampsia. 137 NC women and 58 women with preeclampsia were included in this study. Maternal blood was collected at 3 time points during pregnancy (16-20th weeks, 26-30th weeks and at delivery). Cord blood was collected at delivery. Fatty acids were analyzed using gas chromatography. The proportions of maternal erythrocyte α-linolenic acid, docosahexaenoic acid, nervonic acid, and monounsaturated fatty acids (MUFA) (p < 0.05 for all) were lower while total n-6 fatty acids were higher (p < 0.05) at 16-20th weeks of gestation in preeclampsia as compared with NC. Cord 18:3n-3, 22:6n-3, 24:1n-9, MUFA, and total n-3 fatty acids (p < 0.05 for all) were also lower in preeclampsia as compared with NC. A positive association was observed between maternal erythrocyte 22:6n-3 and 24:1n-9 at 16-20th weeks with the same fatty acids in cord erythrocytes (p < 0.05 for both) in preeclampsia. Our study for the first time indicates alteration in maternal erythrocyte fatty acids at 16th weeks of gestation which is further reflected in cord erythrocytes at delivery in preeclampsia.

Blockade of CD40 ligand for intercellular communication reduces hypertension, placental oxidative stress, and AT1-AA in response to adoptive transfer of CD4+ T lymphocytes from RUPP rats

Preeclampsia (PE) is associated with altered immune activation during pregnancy. We have previously shown that adoptive transfer of CD4(+) T cells from the reduced uterine perfusion pressure (RUPP) rat model of PE increases blood pressure, oxidative stress (ROS), and inflammation in normal pregnant recipient rats. The objective of this study was to determine if blockade of communication via the CD40-CD40 ligand (CD40L) interaction between placental ischemia-induced CD4(+) T cells with endogenous normal pregnant (NP) cells would improve pathophysiology that was previously observed in NP recipient rats of RUPP CD4(+) T cells. Splenic CD4(+) T lymphocytes were magnetically separated, incubated with 2.5 μg/ml anti-CD40 ligand (αCD40L) overnight, and transferred into NP rats on day 12 of gestation (NP+RUPP CD4(+) T+anti-CD40L). On day 19 of gestation, blood pressure (MAP), blood, and tissues were collected. MAP was 99 ± 2 in NP (n = 13), 116 ± 4 in NP+RUPP CD4(+) T cells (n = 7; P < 0.01); MAP only increased to 104 ± 2 in NP+RUPP CD4(+) T cells+CD40L (n = 24) (P < 0.05 vs. NP+RUPP CD4(+) T cells). Mechanisms of hypertension in response to RUPP CD4(+) T cells include endothelin-1 (ET-1), ROS, and angiotensin II type I receptor (AT1-AA) were analyzed. Inhibition of CD40L binding reduced placental ET-1 to 2.3-fold above NP rats and normalized placental ROS from 318.6 ± 89 in NP+RUPP CD4(+) T cells (P < 0.05) to 118.7 ± 24 in NP+RUPP CD4(+) T+anti-CD40L (P < 0.05). AT1-AA was also normalized with inhibition of CD40L. These data suggest that placental ischemia-induced T-cell communication via the CD40L is one important mechanism leading to much of the pathophysiology of PE.

An increased population of regulatory T cells improves the pathophysiology of placental ischemia in a rat model of preeclampsia

The reduced uterine perfusion pressure (RUPP) rat model of preeclampsia exhibits much of the pathology characterizing this disease, such as hypertension, inflammation, suppressed regulatory T cells (TRegs), reactive oxygen species (ROS), and autoantibodies to the ANG II type I receptor (AT1-AA) during pregnancy. The objective of this study was to determine whether supplementation of normal pregnant (NP) TRegs into RUPP rats would attenuate the pathophysiology associated with preeclampsia during pregnancy. CD4(+)/CD25(+) T cells were isolated from spleens of NP and RUPP rats, cultured, and injected into gestation day (GD) 12 normal pregnant rats that underwent the RUPP procedure on GD 14. On GD 1, mean arterial pressure (MAP) was recorded, and blood and tissues were collected for analysis. One-way ANOVA was used for statistical analysis. MAP increased from 99 ± 2 mmHg in NP (n = 12) to 127 ± 2 mmHg in RUPP (n = 21) but decreased to 118 ± 2 mmHg in RUPP+NP TRegs (n = 17). Circulating IL-6 and IL-10 were not significantly changed, while circulating TNF-α and IL-17 were significantly decreased after supplementation of TRegs. Placental and renal ROS were 339 ± 58.7 and 603 ± 88.1 RLU·min(-1)·mg(-1) in RUPP and significantly decreased to 178 ± 27.8 and 171 ± 55.6 RLU·min(-1)·mg(-1), respectively, in RUPP+NP TRegs; AT1-AA was 17.81 ± 1.1 beats per minute (bpm) in RUPP but was attenuated to 0.50 ± 0.3 bpm with NP TRegs. This study demonstrates that NP TRegs can significantly improve inflammatory mediators, such as IL-17, TNF-α, and AT1-AA, which have been shown to increase blood pressure during pregnancy.

Association of common eNOS/NOS3 polymorphisms with preeclampsia in Tunisian Arabs

We investigated the association of endothelial nitric oxide synthase (NOS3) polymorphisms -786T>C, 27-bp repeat 4b/4a, and Glu298Asp with preeclampsia (PE). This was a case-control study involving 345 unrelated Tunisian women with PE and 289 unrelated age- and ethnically matched control women. The -786C allele was significantly increased in PA patients when compared to healthy controls (P=0.015). In contrast, MAF of Glu298Asp (P=0.103) and 4b/4a (P=0.168) were not significantly different between the study groups. Higher frequencies of heterozygous Glu298/298Asp and homozygous -786T/-786T genotypes were seen in PE cases compared to healthy subjects. The combination of genotypes 221 (-786T>C, Glu298Asp, 4a/4a) was more in PE cases compared with control women (17.68% vs. 8.36%; P=0.029). Multivariate regression analysis confirmed this association. Genetic variation at the NOS3 locus represents a genetic risk factor for increased susceptibility to PE.

New insights into the function of Cullin 3 in trophoblast invasion and migration

Cullin 3 (CUL3), a scaffold protein, assembles a large number of ubiquitin ligase complexes, similar to Skp1-Cullin 1-F-box protein complex. Several genetic models have shown that CUL3 is crucial for early embryonic development. Nevertheless, the role of CUL3 in human trophoblast function remains unclear. In this study, immunostaining revealed that CUL3 was strongly expressed in the villous cytotrophoblasts, the trophoblast column, and the invasive extravillous trophoblasts. Silencing CUL3 significantly inhibited the outgrowth of villous explant ex vivo and decreased invasion and migration of trophoblast HTR8/SVneo cells. Furthermore, CUL3 siRNA decreased pro-MMP9 activity and increased the levels of TIMP1 and 2. We also found that the level of CUL3 in the placental villi from pre-eclamptic patients was significantly lower as compared to that from their gestational age-matched controls. Moreover, in the lentiviral-mediated placenta-specific CUL3 knockdown mice, lack of CUL3 resulted in less invasive trophoblast cells in the maternal decidua. Taken together, these results suggest an essential role for CUL3 in the invasion and migration of trophoblast cells, and dysregulation of its expression may be associated with the onset of pre-eclampsia.

IL-10 supplementation increases Tregs and decreases hypertension in the RUPP rat model of preeclampsia

OBJECTIVE

The reduced uterine perfusion pressure (RUPP) rat model of preeclampsia was used to determine the effects of added interleukin-10 (IL-10) on Tregs and hypertension in response to placental ischemia and how the decrease in these anti-inflammatory factors mediates the pathophysiology of preeclampsia.

METHODS

IL-10 (2.5 ng/kg/d) was infused via osmotic mini-pump implanted intraperitoneally on day 14 of gestation and, at the same time, the RUPP procedure was performed.

RESULTS

IL-10 reduced mean arterial pressure (p < 0.001), decreased CD4(+) T cells (p = 0.044), while increasing Tregs (p = 0.043) which led to lower IL-6 and TNF-α (p = 0.008 and p = 0.003), reduced AT1-AA production (p < 0.001), and decreased oxidative stress (p = 0.029) in RUPP rats.

CONCLUSION

These data indicate that IL-10 supplementation increases Tregs and helps to balance the altered immune system seen during preeclampsia.

Nitric oxide dysregulation in the pathogenesis of preeclampsia among Ghanaian women

BACKGROUND

Preeclampsia (PE) is still a disease of theories as the exact cause remains uncertain. Widespread vascular endothelial cell dysfunction is thought to mediate the generalized vasospasm and hypertension characteristic of PE. Altered nitric oxide (NO) production has been associated with the endothelial dysfunction in the pathogenesis of PE but conflicting results have emerged from previous studies.

OBJECTIVES

To determine maternal serum levels of NO, a biomarker of endothelial function, in nonpregnant, normal pregnant, and preeclamptic women.

MATERIALS AND METHODS

This was a cross-sectional case-control study of 277 women comprising 75 nonpregnant, 102 normal pregnant, and 100 preeclamptic women conducted at the Korle Bu Teaching Hospital between April and June 2011. About 5 mL of venous blood was obtained from the participants for the various investigations after meeting the inclusion criteria and signing to a written consent. Serum levels of NO were determined by Griess reaction. The data obtained were analyzed with SPSS version 20.

RESULTS

The study showed significantly elevated serum levels of NO in preeclamptic women (82.45±50.31 μM) compared with normal pregnant (33.12±17.81 μM) and nonpregnant (16.92±11.41 μM) women with P<0.001. The alteration in maternal serum NO levels was significantly more profound in early-onset (severe) PE (119.63±45.860 μM) compared to that of late-onset (mild) disease (62.44±40.44 μM) with P<0.001, indicating a more severe vascular endothelial cell dysfunction in the early-onset disease.

CONCLUSION

This study has determined a profound NO upregulation in PE evidenced by significant elevation of NO metabolite levels compared to normal pregnancy. This might be due to deranged endothelial function with dysregulated production of NO to restore the persistent hypertension characteristic of PE.