An imbalance in the production of proinflammatory and anti-inflammatory cytokines is observed in whole blood cultures of preeclamptic women in comparison with healthy pregnant women

Placental Senescence and the Two-Stage Model of Preeclampsia

In this review, we summarize how an increasingly stressed and aging placenta contributes to the maternal clinical signs of preeclampsia, a potentially lethal pregnancy complication. The pathophysiology of preeclampsia has been conceptualized in the two-stage model. Originally, highlighting the importance of poor placentation for early-onset preeclampsia, the revised two-stage model explains late-onset preeclampsia as well, which is often preceded by normal placentation. We discuss how cellular senescence in the placenta may fit with the framework of the revised two-stage model of preeclampsia pathophysiology and summarize potential cellular and molecular mechanisms, including effects on placental and maternal endothelial function. Cellular senescence may occur in response to inflammatory processes and oxidative, mitochondrial, or endoplasmic reticulum stress and chronic stress induce accelerated, premature placental senescence. In preeclampsia, both circulating and tissue-based senescence markers are present. We suggest that aspirin prophylaxis, commonly recommended from the first trimester onward for women at risk of preeclampsia, may affect placentation and possibly mechanisms of placental senescence, thus attenuating the risk of preeclampsia developing clinically. We propose that biomarkers of placental dysfunction and senescence may contribute to altered preventive strategies, including discontinuation of aspirin at week 24-28 depending on placenta-associated biomarker risk stratification.

Proteomic Analysis of Preeclampsia Amniotic Fluid Based on a Novel Solid-State Preservation Method

Objective: Amniotic fluid (AF) plays a crucial role in diagnosing and predicting perinatal diseases, specifically preeclampsia (PE). Adequate preservation of AF samples is essential for advancing the development of PE-related biomarkers and understanding the disease's mechanisms. Materials and Methods: This study presents a method for preserving proteins in AF on a solid medium, specifically a nitrocellulose membrane, which is referred to as an AF membrane. Samples were collected from normotensive subjects and PE patients and treated with direct freezing and the AF membrane methods, respectively. Protein quality was assessed through sodium dodecyl sulfate-page and capillary electrophoresis. Liquid chromatography tandem mass spectrometry (LC-MS/MS) with data-independent acquisition was employed for proteomic analysis. Bioinformatics analysis identified differentially expressed proteins and pathways distinguishing normotensive subjects from PE patients. Results: Comparison of the AF membrane method to the direct freezing method showed no significant impact on the protein content in the AF. The preservation methods employed did not result in evident protein differences or degradation in the AF obtained from both normotensive subjects and PE patients. Analysis based on Gene Ontology and HALLMARK gene sets revealed the upregulation of pathways associated with angiotensin, reactive oxygen species, and coagulation in PE patients. Furthermore, several biomarkers previously reported to be increased in PE serum, namely ENG, ERN1, FLT1, GDF15, HSPA5, LGALS3, PAPPA, PTX3, and SERPINE1, were significantly elevated in the AF. Conclusion: The AF membrane method proved to be highly effective, reliable, and durable for preserving proteins in AF samples. Preserving AF samples in a solid state holds significant value in discovering novel protein biomarkers and investigating the underlying mechanisms of PE.

Comprehensive Review of Hypertensive Disorders Related to Pregnancy

Hypertensive disorder of pregnancy is a common complication during pregnancy that affects approximately 10% of pregnancies and is responsible for nearly 14% of maternal deaths worldwide. It affects the mother and the fetus simultaneously, sometimes putting the health of the mother and the fetus at odds with each other. It may present with only hypertension and proteinuria or with life-threatening complications in the mother such as eclampsia; stroke; acute pulmonary edema; acute renal failure; disseminated intravascular coagulation; placental abruption; hemolysis, elevated liver enzymes, and low platelet syndrome; pregnancy loss; and fetal growth restriction and prematurity resulting from the frequent need of delivering preterm in the fetus. In this review, we aimed to describe hypertensive disorders of pregnancy, mainly preeclampsia and chronic hypertension in pregnancy, by discussing the pathophysiology, the central role of abnormal placentation, the release of antiangiogenic factors in the circulation and immunological factors, the clinical outcome in the mother and the fetus, and the diagnostic criteria and principles of management of both the conditions. We also discuss possible screening methods and prevention of preeclampsia using low-dose aspirin and eclampsia prophylaxis.

Cytokine-polymorphisms associated with Preeclampsia: A review

BACKGROUND

Preeclampsia (PE) is a syndromic disorder that affects 2% to 8% of pregnancies and is diagnosed principally when hypertension appears in the second-d half of pregnancy. WHO estimates the incidence of PE to be seven times higher in developing countries than in developed countries. Severe preeclampsia/eclampsia is one of the most important causes of maternal mortality, associated with 50,000 to 100,000 annual deaths globally as well as serious fetal and neonatal morbidity and mortality, especially in developing countries. Even though evidence from family-based studies suggest PE has a heritable component, its etiology, and specific genetic contributions remain unclear. Many studies examining the genetic factors contributing to PE have been conducted, most of them are focused on single nucleotide polymorphisms (SNPs). Given that PE has a very important inflammatory component, is mandatory to examine cytokine-SNPs for elucidating all mechanisms involved in this pathology. In this review, we describe the most important cytokine-polymorphisms associated with the onset and development of PE. We aim to provide current and relevant evidence in this regard.

METHODS

We searched English databases such as PubMed and the National Center for Biotechnology Information. The publication time of the papers was set from the establishment of the databases to February 2022. All studies about Th1/Th2/Th17 cytokines polymorphisms were included in our study.

RESULTS

SNPs in IFN-γ, TNF-α, IL-4, IL-6, IL-10, IL-17A, and IL-22 are associated with the development, early-onset and severity of PE, being the Th1/Th2/Th17 responses affected by the presence of these SNPs.

CONCLUSIONS

The changes in Th1/Th2/Th17 response modify processes such as placentation, control of inflammation, and vascular function. Nonetheless, association studies have shown different results depending on sample size, diagnostic, and population.

Decreased expression of caveolin-1 have relevance to promoted senescence in preeclamptic placenta

OBJECTIVES

To assess the association between altered expression of caveolin-1 and p53/p21, as indicatives of cellular senescence, in preeclamptic placenta.

STUDY DESIGN

Placental tissues and serum were collected from rats (Sham and reduced uterine perfusion pressure group) at 18.5 days post coitum and humans (normotensive pregnant and preeclampsia groups). The concentration and expression of caveolin-1 were measured in the collected tissues, and the correlation between p53 and p21 expression was evaluation.

MAIN OUTCOME MEASURES

Placental mRNA expression and serum concentration of caveolin-1 were measured using qRT-PCR and ELISA, respectively. Altered expressions of caveolin-1 and p53/p21 were revealed and quantified by immunohistochemistry. The association between these changes was investigated using correlation analysis.

RESULTS

Placental mRNA expressions and serum concentrations of caveolin-1 were significantly decreased in reduced uterine perfusion pressure and preeclampsia groups. The expressions of caveolin-1 and p53/ p21 were significantly altered in placenta complicated with preeclampsia. Correlation analysis revealed a significant inverse association between changes in caveolin-1 and p53/p21. Subsequently, these results were obtained by investigating the preeclampsia onset time.

CONCLUSION

These results revealed that the expression of caveolin-1 profoundly decreases in the placenta and serum of preeclampsia. These factors contribute to the mechanism of accelerated cellular senescence in placenta, which is one of the various etiologies of preeclampsia.

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.

The intervention effect of aspirin on a lipopolysaccharide-induced preeclampsia-like mouse model by inhibiting the nuclear factor-κB pathway

Preeclampsia is a severe pregnancy-related disorder, and patients usually present with high circulating inflammatory factor levels and excessive activation of the nuclear factor-κB (NF-κB) pathway. Administration of aspirin (ASP) is effective for preventing preeclampsia, and thus, we propose that ASP might affect placental function by regulating the NF-κB pathway. Systemic lipopolysaccharide (LPS) (20 μg/kg) was used to induce preeclampsia-like pregnant mouse model, and low-dose ASP (15.2 mg/kg) was administrated. Here, we report significantly increased circulatory expression levels of the proinflammatory cytokines tumor necrosis factor-alpha, interleukin-6, and soluble Fms-related tyrosine kinase-1 in LPS-treated pregnant mice, accompanied by kidney and placental dysfunction. Low-dose ASP treatment significantly reversed the preeclampsia-like phenotype, lowering hypertension, decreasing proteinuria, and ameliorating fetal growth retardation. Moreover, the excessive activation of NF-κB signaling in mice placentae induced by LPS was significantly reduced by ASP. In JEG-3 cells, LPS activated the NF-κB signaling pathway by upregulating the expression of cyclooxygenase-2 (COX-2) and related inflammatory factors, whereas the invasion ability of JEG-3 cells was weakened. However, ASP administration impeded NF-κB signaling activation, downregulated COX-2 and inflammatory factor expression, and rescued trophoblast invasion. This study provides new evidence that low-dose ASP is beneficial for preeclampsia prevention by inhibiting NF-κB and its downstream signaling pathways in trophoblast cells.

Glutathione-S-transferase M1 polymorphism and pro-inflammatory cytokines tumour necrosis factor-α and interleukin-1β are associated with preeclampsia in Serbian women

PROBLEM

Preeclampsia has a multifactorial origin with genetic, immunological, and environmental factors described as main contributors to its onset. This study aimed to investigate glutathione-S-transferase M1 (GSTM1) and glutathione-S-transferase T1 (GSTT1) gene polymorphisms, the expression of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6), and the potential relationship between GST polymorphisms and cytokine expression levels in preeclampsia and uncomplicated pregnancy.

METHOD OF STUDY

This prospective case-control study included 50 women with preeclampsia and 50 healthy pregnant women. DNA and RNA were extracted from women leukocytes. Deletion polymorphisms were analyzed by PCR, while cytokine mRNA expression was analyzed by real-time PCR.

RESULTS

GSTM1 null genotype with present GSTT1 increased the risk for preeclampsia development. Deletion of GSTT1 without deletion of GSTM1 increased the risk for early preeclampsia. Relative mRNA expression of TNF-α was significantly higher in preeclampsia compared to healthy pregnant women (P = 0.006). Expression of IL-1β was significantly higher in severe and late preeclampsia compared to the control group (P = 0.005, P = 0.007, respectively). A significant positive correlation between TNF-α and IL-1β was observed (Spearman's ρ = 0.312, P = 0.028) and between IL-1β and IL-6, in preeclampsia group (Spearman's ρ = 0.296, P = 0.037). IL-1β was significantly increased in patients with GSTT1 null genotype (P = 0.015) while IL-6 was increased in patients with GSTM1 null genotype (P = 0.015).

CONCLUSIONS

GSTM1 null genotype represents a risk factor for preeclampsia development, while GSTT1 null genotype favors early preeclampsia. Preeclampsia is also associated with increased expression of pro-inflammatory cytokines, predominantly TNF-α and IL-1β.

The role of interleukins in preeclampsia: A comprehensive review

Preeclampsia is a multi-system hypertensive disorder of pregnancy, with significant rates of maternal and neonatal morbidity. It represents a major cause of preterm birth, as definitive treatment demands fetal delivery. Although its pathophysiology is complicated, placental hypoxia and endothelial dysfunction constitute established pathogenetic steps of the disease. Inflammation is considered to be a crucial mediator of preeclampsia process, as an imbalance between T_H 1, T_H 2, and T_H 17 immune responses is observed. The present review accumulates current knowledge about the contribution of interleukins in preeclampsia, summarizing the pathways through which each interleukin exerts its function in the disease. Also, the role of genetic polymorphisms is explored and the predictive efficacy of maternal serum interleukin levels is evaluated. Finally, recommendations about the safe interpretation of the outcomes, as well as guidance for future research, are provided.

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.

Is there a role for placental senescence in the genesis of obstetric complications and fetal growth restriction?

The placenta ages as pregnancy advances, yet its continued function is required for a successful pregnancy outcome. Placental aging is a physiological phenomenon; however, there are some placentas that show signs of aging earlier than others. Premature placental senescence and aging are implicated in a number of adverse pregnancy outcomes, including fetal growth restriction, preeclampsia, spontaneous preterm birth, and intrauterine fetal death. Here we discuss cellular senescence, a state of terminal proliferation arrest, and how senescence is regulated. We also explore the role of physiological placental senescence and how aberrant placental senescence alters placental function, contributing to the pathophysiology of fetal growth restriction, preeclampsia, spontaneous preterm labor/birth, and unexplained fetal death.

Maternal Micronutrients, Omega-3 Fatty Acids and Gene Expression of Angiogenic and Inflammatory Markers in Pregnancy Induced Hypertension Rats

BACKGROUND AND AIMS

Preeclampsia is a disorder of pregnancy and is associated with inflammation and altered angiogenesis. The present study examines the effect of micronutrient and omega-3 fatty acid supplementation (individual, as well as combined) on genes involved in inflammation and angiogenesis, as well as global DNA methylation levels in a pregnancy induced hypertension (PIH) rat model.

METHODS

Pregnant Wistar rats were randomly assigned to six dietary groups: control, PIH (Pregnancy induced hypertension) Induced; PIH Induced with micronutrient supplements with vitamin B₁₂ (PIHB), folate (PIHF), omega-3 fatty acid (PIHO), and combined supplementation (PIHC) (micronutrients and omega-3 fatty acids). Half the dams were dissected on 20 d of gestation to collect placental tissue, and half were allowed to deliver normally on 22 d of gestation and were assigned to a postnatal control diet. The offspring were dissected at 3 month of age.

RESULTS

PIH induction increased the mRNA levels of the pro inflammatory cytokine IL-6 (p <0.01), while lowering the placental anti inflammatory cytokine IL-10 (p <0.05) at d20 of gestation. It also increased the expression of TNF-α (p <0.05) in the liver of 3 month old offspring. The combined supplementation of folic acid, vitamin B₁₂ and omega-3 fatty acids improved placental IL-10 levels and decreased TNF-α levels in offspring livers.

CONCLUSION

Our data indicate that a combined supplementation of vitamin B₁₂, folic acid and omega-3 fatty acid was useful for the better management of preeclampsia in an animal model.

Simvastatin Alleviates Pathology in a Rat Model of Preeclampsia Involving ERK/MAPK Pathway

Preeclampsia (PE) is a pregnancy-specific condition characterized by new-onset hypertension. There is evidence suggesting that imbalances of angiogenic factors, oxidative stress, and inflammation may be central to the pathogenesis of PE. We sought to investigate whether simvastatin would reduce mean arterial pressure, restore the angiogenic balance, and ameliorate inflammation and oxidative stress in a nitric oxide synthase inhibitor NG-nitro-l-arginine methyl ester (l-NAME)-induced rat model of PE. We found that blood pressure was significantly increased in the l-NAME group compared to normal pregnant dams ( P < .01), and simvastatin reduced this difference. In addition, dams from the l-NAME group showed lower vascular endothelial growth factor (VEGF) and interleukin (IL) 10 levels and higher plasma-soluble FMS-like tyrosine kinase 1 (sFlt-1), tumor necrosis factor α (TNF-α), and oxidative stress marker malondialdehyde (MDA) levels as compared to control dams ( P < .01, for all). Interestingly, simvastatin treatment significantly increased VEGF and IL-10 levels while decreased sFlt-1, TNF-α, and MDA levels compared to the untreated l-NAME group. Moreover, simvastatin treatment significantly upregulated protein expression of placental p-extracellular signal-regulated kinase (ERK1), p-p38 mitogen-activated protein kinase (MAPK), p-c-Jun N-terminal kinase, and p-protein kinase B compared to untreated l-NAME control. These results suggest that simvastatin treatment restores angiogenic balance and ameliorates inflammation and oxidative stress in a rat model of PE involving ERK/MAPK pathway.

Vitamin D restores angiogenic balance and decreases tumor necrosis factor-α in a rat model of pre-eclampsia

AIM

Deficiency of vitamin D is correlated with pre-eclampsia (PE), a hypertensive disorder of pregnancy, and is characterized by angiogenic imbalance and inflammation. The aim of this study was to investigate whether vitamin D supplementation can restore the angiogenic balance and ameliorate inflammation in a rat model of PE.

METHODS

PE was induced using l-nitroarginine methylester. Normal pregnant and PE-induced rats were supplemented with vitamin D on gestation days 14-19.

RESULTS

Blood pressure was significantly increased in PE-induced rats compared with normal pregnant rats (P < 0.05), and vitamin D supplementation ameliorated this difference. In addition, rats from the PE group had lower vascular endothelial growth factor (VEGF; P < 0.01), and higher plasma-soluble FMS-like tyrosine kinase-1 (sFlt-1) and tumor necrosis factor-α (TNF-α; P < 0.01 for both) compared with the normal pregnant group. The vitamin D treatment group had significantly increased VEGF, and reduced sFlt-1 and TNF-α compared with the untreated PE group. Moreover, vitamin D supplementation was able to reduce the oxidative stress by lowering the plasma oxidative stress marker malondialdehyde.

CONCLUSION

Vitamin D supplementation plays an important role in restoring angiogenic balance and reducing inflammation in pregnancy-induced hypertension.

Supplementation of maternal omega-3 fatty acids to pregnancy induced hypertension Wistar rats improves IL10 and VEGF levels

OBJECTIVES

Our recent study demonstrates the beneficial effect of a combined supplementation of vitamin B12, folic acid, and docosahexaenoic acid in reducing the severity of pregnancy induced hypertension (PIH). It is also known to be associated with angiogenic imbalance and inflammation. The current study examines whether the individual/combined supplementation of folic acid, vitamin B12 and omega-3 fatty acid during pregnancy can ameliorate the inflammatory markers and restore the angiogenic balance in a rat model of PIH.

MATERIALS AND METHODS

There were total of six groups, control and five treatment groups: PIH Induced; PIH+vitamin B12; PIH+folic acid; PIH+Omega-3 fatty acids and PIH+combined micronutrient supplementation (vitamin B12+folic acid+omega-3 fatty acids). Hypertension during pregnancy was induced using L- Nitroarginine methylester (L-NAME; 50mg/kg body weight/day). Dams were dissected at d20 of gestation and placental tissues were collected for further analysis.

RESULTS

Animals from the PIH induced group demonstrated lower (p<0.01 for both) IL-10 and VEGF levels as compared to control. However, PIH induction did not alter the protein levels of eNOS, IL-6, Flt and mRNA levels of VEGF and VEGFR-1/ Flt-1. Individual micronutrient supplementation of vitamin B12 and folate did not offer benefit. In contrast individual omega-3 fatty acid as well as combined micronutrient supplementation showed IL-10 and VEGF levels comparable to that of control.

CONCLUSION

Omega 3 fatty acid supplementation plays a key role in reducing inflammation in pregnancy induced hypertension.

Interleukin-22: biomarker of maternal and fetal inflammation?

Histologic chorioamnionitis (HCA) is an intrauterine status of inflammation which may lead to the fetal inflammatory response syndrome. Inflammation is a pathogenetic mechanism also of preeclampsia, although not of microbial origin. The aim of the present pilot study was to evaluate the pattern of inflammatory cytokines in mothers and high-risk preterm infants during the perinatal period. Concentrations of proinflammatory and anti-inflammatory cytokines and C-reactive protein were evaluated in maternal, cord, and neonatal blood of very preterm infants <1,500 g birth weight. Histologic examinations of placentae and umbilical cords were performed. The 65 mother-neonate pairs enrolled were subdivided into three groups: (1) HCA group (n = 15), (2) preeclampsia group (n = 17), and (3) control group, in the absence of HCA/preeclampsia (n = 33). Maternal Interleukin (IL)-6 levels were significantly higher in women of the HCA group compared with the preeclampsia and control groups (p < 0.05). IL-22 was detected in nearly all maternal samples [median value 693.115 pg/ml (599.91-809.91 pg/ml)], with no statistical difference between the groups, but with a tendency to increased levels among preeclamptic women. Increased concentrations of IL-22 were detected in cord blood of neonates exposed to preeclampsia, compared with controls and infants exposed to HCA (p < 0.05). We speculate that the tendentially higher concentrations of IL-22 in preeclamptic mothers and the significantly higher concentrations in cord blood may reflect placental dysfunction and the underlying reparative processes at the maternal-fetal interface. Therefore, IL-22 could be an important biomarker of inflammation in preeclampsia.

Association between CRP gene polymorphisms and the risk of preeclampsia in Han Chinese women

BACKGROUND

As an inflammatory marker, C-reactive protein (CRP) has elevated expression in preeclampsia (PE), which is implicated in the pathogenesis of PE, but there has been a lack of information on the possible association between genetic variants of CRP and PE. In this study, we aimed to assess the genetic association between CRP polymorphisms and the risk of PE in Han Chinese Women.

METHODS

Five single-nucleotide polymorphisms of CRP, rs2794521 (T>C), rs3091244 (C>T>A), rs3093068 (C>G), rs876538 (C>T), and rs1205 (C>T) were genotyped using the Sequenom method in 181 PE patients and 203 controls.

RESULTS

The T allele frequency for rs2794521 was significantly higher in PE patients than in controls (odds ratios [OR]=4.091; 95% confidence interval [CI]: 1.533-10.917; p=0.002). The TT genotype of rs2794521 conferred a risk for PE (TT vs. TC+CC: OR=4.062; 95% CI: 1.499-11.008; p=0.003) and severe PE (TT vs. TC+CC: OR=9.577; 95% CI: 1.267-72.397; p=0.006). The other four polymorphic loci were not different between the groups. The CRP H2 haplotype (T-C-C-G-C) was associated with PE (OR=2.129; 95% CI: 1.47-3.085; p<0.001), whereas the H1 haplotype (C-C-C-G-C) offered protection (OR=0.23; 95% CI: 0.066-0.8; p=0.01).

CONCLUSIONS

The CRP variant rs2794521 shows a strong association with PE in Han Chinese women. Pregnant women with the TT genotype of rs2794521 have higher odds of having PE, which further supports a possible role for CRP in PE.