The genetic component of preeclampsia: A whole-exome sequencing study

A Narrative Review on the Pathophysiology of Preeclampsia

Preeclampsia (PE) is a multifactorial pregnancy disorder characterized by hypertension and proteinuria, posing significant risks to both maternal and fetal health. Despite extensive research, its complex pathophysiology remains incompletely understood. This narrative review aims to elucidate the intricate mechanisms contributing to PE, focusing on abnormal placentation, maternal systemic response, oxidative stress, inflammation, and genetic and epigenetic factors. This review synthesizes findings from recent studies, clinical trials, and meta-analyses, highlighting key molecular and cellular pathways involved in PE. The review integrates data on oxidative stress biomarkers, angiogenic factors, immune interactions, and mitochondrial dysfunction. PE is initiated by poor placentation due to inadequate trophoblast invasion and improper spiral artery remodeling, leading to placental hypoxia. This triggers the release of anti-angiogenic factors such as soluble fms-like tyrosine kinase-1 (sFlt-1) and soluble endoglin (sEng), causing widespread endothelial dysfunction and systemic inflammation. Oxidative stress, mitochondrial abnormalities, and immune dysregulation further exacerbate the condition. Genetic and epigenetic modifications, including polymorphisms in the Fms-like tyrosine kinase 1 (FLT1) gene and altered microRNA (miRNA) expression, play critical roles. Emerging therapeutic strategies targeting oxidative stress, inflammation, angiogenesis, and specific molecular pathways like the heme oxygenase-1/carbon monoxide (HO-1/CO) and cystathionine gamma-lyase/hydrogen sulfide (CSE/H2S) pathways show promise in mitigating preeclampsia's effects. PE is a complex disorder with multifactorial origins involving abnormal placentation, endothelial dysfunction, systemic inflammation, and oxidative stress. Despite advances in understanding its pathophysiology, effective prevention and treatment strategies remain limited. Continued research is essential to develop targeted therapies that can improve outcomes for both mothers and their babies.

Disruption of maternal vascular remodeling by a fetal endoretrovirus-derived gene in preeclampsia

BACKGROUND

Preeclampsia, one of the most lethal pregnancy-related diseases, is associated with the disruption of uterine spiral artery remodeling during placentation. However, the early molecular events leading to preeclampsia remain unknown.

RESULTS

By analyzing placentas from preeclampsia, non-preeclampsia, and twin pregnancies with selective intrauterine growth restriction, we show that the pathogenesis of preeclampsia is attributed to immature trophoblast and maldeveloped endothelial cells. Delayed epigenetic reprogramming during early extraembryonic tissue development leads to generation of excessive immature trophoblast cells. We find reduction of de novo DNA methylation in these trophoblast cells results in selective overexpression of maternally imprinted genes, including the endoretrovirus-derived gene PEG10 (paternally expressed gene 10). PEG10 forms virus-like particles, which are transferred from the trophoblast to the closely proximate endothelial cells. In normal pregnancy, only a low amount of PEG10 is transferred to maternal cells; however, in preeclampsia, excessive PEG10 disrupts maternal vascular development by inhibiting TGF-beta signaling.

CONCLUSIONS

Our study reveals the intricate epigenetic mechanisms that regulate trans-generational genetic conflict and ultimately ensure proper maternal-fetal interface formation.

Study of heart function in PRE-Eclampsia during and after PreGnancy (SHePREG): The pilot cohort

BACKGROUND

Pre-eclampsia with severe features (severe PreE) is associated with heart dysfunction, yet the impact beyond pregnancy, including its association with cardiomyopathic genetic polymorphisms, remains poorly understood.

OBJECTIVE

We aimed to characterize the temporal impact of severe PreE on heart function through the 4th trimester in women with and without deleterious cardiomyopathic genetic variants.

METHODS

Pregnant women were enrolled to undergo transthoracic echocardiography (TTE) in late pregnancy and 3 months postpartum. In women with severe PreE a targeted approach to identify pathogenic cardiomyopathic genetic polymorphisms was undertaken, and heart function was compared in carriers and noncarriers.

RESULTS

Pregnant women (32 ± 4 years old, severe PreE = 14, control = 8) were enrolled between 2019 - 2021. Women with severe PreE displayed attenuated myocardial relaxation (mitral e' = 11.0 ± 2.2 vs 13.2 ± 2.3 cm/sec, P < .05) in late pregnancy, and on in-silico analysis, deleterious cardiomyopathic variants were found in 58%. At 103 ± 33 days postpartum, control women showed stability in myocardial relaxation (Mitral e' Entry: 13.2 ± 2.3 vs Postpartum: 13.9 ± 1.7cm/sec, P = .464), and genetic negative severe PreE women (G-) demonstrated recovery of diastolic function to control level (Mitral e' Entry: 11.0 ± 3.0 vs Postpartum 13.7 ± 2.8cm/sec, P < .001), unlike their genetic positive (G+) counterparts (Mitral e' Entry: 10.5 ± 1.7 vs Postpartum 10.8 ± 2.4cm/sec, P = .853).

CONCLUSIONS

Postpartum recovery of heart function after severe PreE is attenuated in women with deleterious cardiomyopathic genetic polymorphisms.

Pregnancy as a susceptible state for thrombotic microangiopathies

Pregnancy and the postpartum period represent phases of heightened vulnerability to thrombotic microangiopathies (TMAs), as evidenced by distinct patterns of pregnancy-specific TMAs (e.g., preeclampsia, HELLP syndrome), as well as a higher incidence of nonspecific TMAs, such as thrombotic thrombocytopenic purpura or hemolytic uremic syndrome, during pregnancy. Significant strides have been taken in understanding the underlying mechanisms of these disorders in the past 40 years. This progress has involved the identification of pivotal factors contributing to TMAs, such as the complement system, ADAMTS13, and the soluble VEGF receptor Flt1. Regardless of the specific causal factor (which is not generally unique in relation to the usual multifactorial origin of TMAs), the endothelial cell stands as a central player in the pathophysiology of TMAs. Pregnancy has a major impact on the physiology of the endothelium. Besides to the development of placenta and its vascular consequences, pregnancy modifies the characteristics of the women's microvascular endothelium and tends to render it more prone to thrombosis. This review aims to delineate the distinct features of pregnancy-related TMAs and explore the contributing mechanisms that lead to this increased susceptibility, particularly influenced by the "gravid endothelium." Furthermore, we will discuss the potential contribution of histopathological studies in facilitating the etiological diagnosis of pregnancy-related TMAs.

10. Role of high dimensional technology in preeclampsia (omics in preeclampsia)

Preeclampsia is a pregnancy-specific disease that has no known precise cause. Integrative biology approach based on multi-omics has been applied to identify upstream pathways and better understand the pathophysiology of preeclampsia. At DNA level, genomics and epigenomics studies have revealed numerous genetic variants associated with preeclampsia, including those involved in regulating blood pressure and immune response. Transcriptomics analyses have revealed altered expression of genes in preeclampsia, particularly those related to inflammation and angiogenesis. At protein level, proteomics studies have identified potential biomarkers for preeclampsia diagnosis and prediction in addition to revealing the main pathophysiological pathways involved in this disease. At metabolite level, metabolomics has highlighted altered lipid and amino acid metabolisms in preeclampsia. Finally, microbiomics studies have identified dysbiosis in the gut and vaginal microbiota in pregnant women with preeclampsia. Overall, omics technologies have improved our understanding of the complex molecular mechanisms underlying preeclampsia. However, further research is warranted to fully integrate and translate these omics findings into clinical practice.

Determinants of pre-eclampsia among pregnant women attending antenatal care and delivery services at Bahir Dar public hospitals, northwest Ethiopia: A case-control study

Background and Aims

Pre-eclampsia (PE) is a pregnancy-related syndrome that occurs after 20 weeks of pregnancy. The current study was designed to evaluate the determinants of PE in pregnant women following antenatal and delivery services.

Methods

An institution-based case-control study was performed in governmental hospitals of Bahir Dar city. The data were collected using an interview-administered questionnaire and analyzed by SPSS version 20 software. Bivariate and multivariable logistic regression models were utilized for the analysis of variables. A p < 0.05 was used to declare the level of significance.

Results

In this study, the mean ages (in years) of cases and controls were 28.20 ± 5.66 and 27.52 ± 4.70, respectively. Factors such as: being primiparous (adjusted odds ratio [AOR]: 3.19 at 95% confidence interval [CI]: 1.71, 5.97), family history of hypertension (HTN) (AOR: 4.14 at 95% CI: 1.71, 10.05), previous history of PE (AOR: 7.97 at 95% CI: 2.42, 26.63), number of antenatal care (ANC) visits (AOR: 5.43 at 95% CI: 2.86, 10.33), not taking iron and folic acid supplement (AOR: 4.46 at 95% CI: 1.59, 12.48), body mass index ≥25 kg/m² (AOR: 3.47 at 95% CI: 1.78, 6.77), not consuming vegetables (AOR: 1.99 at 95% CI: 1.07, 3.69) and not consuming egg, milk and milk products (AOR: 3.00 at 95% CI: 1.47, 6.11) were the determinants of PE.

Conclusion

In this study, different determinants of PE were identified. Hence, special attention should be given for primiparous women, women having previous history of PE and family history of HTN. Moreover, nutritional counseling should be given for pregnant women during ANC visits. Besides, higher officials should design an appropriate strategy to increase the number of mothers to complete their ANC visits and to take iron and folic acid supplements. Furthermore, to verify the determinants of PE, community-based cohort studies are warranted.

STOX1 promotor region -922 T > C polymorphism is associated with Early-Onset preeclampsia

Preeclampsia (PE), affecting 5-8% of pregnancies, is a common pregnancy disease that has harmful effects on mother and foetus. It has been found that the STOX1 (Storkhead Box 1), which is a transcription factor, carries variants associated with PE. Previous studies showed that, there was a strong relationship between PE and STOX1 variants. Therefore, we hypothesised that variants in the promoter region of the gene may be related to the onset of PE. The aim of this study is to investigate the contribution of STOX1 gene promoter region variants to PE. The blood samples taken from 118 PE patients and 96 healthy pregnant women were analysed by Sanger sequencing method. Sequence analysis results showed that, there is a-922 T > C polymorphism (rs884181) in the promoter region of the STOX1 gene. This polymorphism was found to be statistically significant in individuals with early onset PE (p = 0.02) and in PE (p = 0.014) compared to the control group.IMPACT STATEMENTWhat is already known on this subject? As a result of whole-exon studies on the STOX1 gene, polymorphisms were found to disrupt the structure/expression/function of the gene and strengthen its relationship with PE and HELLP syndrome. A previous study by our team found an association between Y153H, the most common polymorphism of STOX1, and early onset PE.What do the results of this study add? In our study, it was aimed to investigate the effect of genetic modifications in STOX1 gene promoter region on PE through the maternal genotype. Because any change in the promoter region affects the expression level of the gene. Also, for the first time, sequence analysis of the promoter region of STOX1 is investigated in PE. The variations in STOX1 appear to be important in PE especially in Early Onset PE.What are the implications of these findings for clinical practice and/or further research? Although PE is a disease that occurs with pregnancy and shows its effects most during this period, women and children with a history of PE are more prone to various disorders, especially cardiovascular diseases in the following years. Therefore, understanding the pathogenesis of the disease is important for both prevention and treatment process. Variations on STOX1 appear to be important in terms of disease risk.

Protein Network Analysis of Whole Exome Sequencing of Severe Preeclampsia

Preeclampsia is a hypertensive disorder of pregnancy, which complicates up to 15% of US deliveries. It is an idiopathic disorder associated with several different phenotypes. We sought to determine if the genetic architecture of preeclampsia can be described by clusters of patients with variants in genes in shared protein interaction networks. We performed a case-control study using whole exome sequencing on early onset preeclamptic mothers with severe clinical features and control mothers with uncomplicated pregnancies between 2016 and 2020. A total of 143 patients were enrolled, 61 women with early onset preeclampsia with severe features based on ACOG criteria, and 82 control women at term, matched for race and ethnicity. A network analysis and visualization tool, Proteinarium, was used to confirm there are clusters of patients with shared gene networks associated with severe preeclampsia. The majority of the sequenced patients appear in two significant clusters. We identified one case dominant and one control dominant cluster. Thirteen genes were unique to the case dominated cluster. Among these genes, LAMB2, PTK2, RAC1, QSOX1, FN1, and VCAM1 have known associations with the pathogenic mechanisms of preeclampsia. Using bioinformatic analysis, we were able to identify subsets of patients with shared protein interaction networks, thus confirming our hypothesis about the genetic architecture of preeclampsia.

Fetal Cerebral Hemodynamic Changes in Preeclampsia Patients by Ultrasonic Imaging under Intelligent Algorithm

This study was aimed at evaluating the adoption value of ultrasound imaging features on fetal cerebral hemodynamics in preeclampsia patients based on the partial difference algorithm and the hybrid segmentation network (HSegNet) algorithm. Forty pregnant women with preeclampsia diagnosed by ultrasound examination were selected as the research objects, and another forty normal pregnant women were selected as the control. Then, by using the partial differential algorithm, the imaging of fetal cerebral hemodynamics in preeclampsia patients was enhanced and optimized, and the general clinical data and experimental results were collected. The results showed that the automatic labeling of fetal cerebral artery in fetal middle cerebral artery (MCA) hemodynamic images was realized by HSegNet algorithm model, and the final accuracy was 97.3%, which had a good consistency with the manual annotation of doctors. Education level was a protective factor for preeclampsia (odds ratio (OR) = 0.535). Body mass index (BMI) and family history of hypertension during pregnancy were independent risk factors for preeclampsia (OR = 1.286, and 2.774, respectively). MCA end-diastolic volume (EDV) of preeclampsia fetuses was higher than that of normal fetuses. The MCA systolic-diastolic ratio (S/D), the pulsatility index (PI), and the resistive index (RI) in the preeclampsia group were significantly lower than those in the normal pregnancy group. The results showed that MCA PI, MCA RI, and MCA S/D had certain predictive values for the occurrence of adverse pregnancy outcomes (P < 0.05). In summary, the intelligent algorithm-based fetal MCA hemodynamic ultrasound image in the study could effectively predict pregnancy outcomes of patients and provide certain theoretical support for the subsequent reduction of adverse pregnancy outcomes in patients with preeclampsia.

Preeclampsia and eclampsia: the conceptual evolution of a syndrome

Preeclampsia, one of the most enigmatic complications of pregnancy, is considered a pregnancy-specific disorder caused by the placenta and cured only by delivery. This article traces the condition from its origins-once thought to be a disease of the central nervous system, recognized by the occurrence of seizures (ie, eclampsia)-to the present time when preeclampsia is conceptualized primarily as a vascular disorder. We review the epidemiologic data that led to the recommendation to use diastolic hypertension and proteinuria as diagnostic criteria, as their combined presence was associated with an increased risk of fetal death and the birth of small-for-gestational-age neonates. However, preeclampsia is a multisystemic disorder with protean manifestations, and the condition can be present even in the absence of hypertension and proteinuria. Toxins gaining access to the maternal circulation have been proposed to mediate the clinical manifestations-hence, the term "toxemia of pregnancy," which was used for several decades. The search for putative toxins has challenged investigators for more than a century, and a growing body of evidence suggests that products of an ischemic or a stressed placenta are responsible for the vascular changes that characterize this syndrome. The discovery that the placenta can produce antiangiogenic factors, which regulate endothelial cell function and induce intravascular inflammation, has been a major step forward in the understanding of preeclampsia. We view the release of antiangiogenic factors by the placenta as an adaptive response to improve uterine perfusion by modulating endothelial function and maternal cardiovascular performance. However, this homeostatic response can become maladaptive and lead to damage of target organs during pregnancy or the postpartum period. Early-onset preeclampsia has many features in common with atherosclerosis, whereas late-onset preeclampsia seems to result from a mismatch of fetal demands and maternal supply, that is, a metabolic crisis. Preeclampsia, as it is understood today, is essentially vascular dysfunction unmasked or caused by pregnancy. A subset of patients diagnosed with preeclampsia are at greater risk of the subsequent development of hypertension, ischemic heart disease, heart failure, vascular dementia, and end-stage renal disease. However, these adverse events may be the result of a preexisting vascular pathologic process; it is not known if the occurrence of preeclampsia increases the baseline risk. Therefore, the understanding, prediction, prevention, and treatment of preeclampsia are healthcare priorities.

Genetic predisposition to hypertension is associated with preeclampsia in European and Central Asian women

Preeclampsia is a serious complication of pregnancy, affecting both maternal and fetal health. In genome-wide association meta-analysis of European and Central Asian mothers, we identify sequence variants that associate with preeclampsia in the maternal genome at ZNF831/20q13 and FTO/16q12. These are previously established variants for blood pressure (BP) and the FTO variant has also been associated with body mass index (BMI). Further analysis of BP variants establishes that variants at MECOM/3q26, FGF5/4q21 and SH2B3/12q24 also associate with preeclampsia through the maternal genome. We further show that a polygenic risk score for hypertension associates with preeclampsia. However, comparison with gestational hypertension indicates that additional factors modify the risk of preeclampsia.

Identifying new potential genetic biomarkers for HELLP syndrome using massive parallel sequencing

BACKGROUND

Preeclampsia (PE) is a frequently occurring multisystemic disease affecting ~5% of pregnancies. PE patients may develop HELLP syndrome (haemolysis, elevated liver enzymes, and low platelet), a mother and foetus life-threatening condition. Research into HELLP's genetic origin has been relatively unsuccessful, mainly because normal placental function and blood pressure regulation involve the fine-regulation of hundreds of genes.

OBJECTIVE

To identify new genes and mutations constituting potential biomarkers for HELLP syndrome.

STUDY DESIGN

The present case-control study involved whole-exome sequencing of 79 unrelated HELLP women. Candidate variants were screened in a control population constituted by 176 individuals. Stringent bioinformatics filters were used for selecting potentially etiological sequence variants in a subset of 487 genes. We used robust in silico mutation modelling for predicting the potential effect on protein structure.

RESULTS

We identified numerous sequence variants in genes related to angiogenesis/coagulation/blood pressure regulation, cell differentiation/communication/adhesion, cell cycle and transcriptional gene regulation, extracellular matrix biology, lipid metabolism and immunological response. Five sequence variants generated premature stop codons in genes playing an essential role in placental physiology (STOX1, PDGFD, IGF2, MMP1 and DNAH11). Six variants (ERAP1- p.Ile915Thr, ERAP2- p.Leu837Ser, COMT-p.His192Gln, CSAD-p.Pro418Ser, CDH1- p.Ala298Thr and CCR2-p.Met249Lys) led to destabilisation of protein structure as they had significant energy and residue interaction-related changes. We identified at least two mutations in 57% of patients, arguing in favour of a polygenic origin for the HELLP syndrome.

CONCLUSION

Our results provide novel evidence regarding PE/HELLP's genetic origin, leading to new biomarkers, having potential clinical usefulness, being proposed.

Pregnancy as a model for aging

The process of aging can be defined as the sum accumulation of damages and changes in metabolism during the life of an organism, due to both genetic predisposition and stochastic damage. During the gestational period and following parturition, similar damage can be seen due to the strenuous effect on the maternal body, exhibited on both the physiological and cellular level. In this review, we will focus on the similar physiological and cellular characteristics exhibited during pregnancy and aging, including induction of and response to oxidative stress, inflammation, and degradation of telomeres. We will evaluate any similar processes between aging and pregnancy by comparing common biomarkers, pathologies, and genetic and epigenetic effects, to establish the pregnant body as a model for aging. This review will approach the connection both in respect to current theories on aging as a byproduct of natural selection, and regarding unrelated biochemical similarities between the two, drawing on existing studies and models in humans and other species where relevant alike. Furthermore, we will show the response of the pregnant body to these changes, and through that illuminate unique areas of potential study to advance our knowledge of the maladies relating to aging and pregnancy, and an avenue for solutions.

Whole-exome sequencing in multiplex preeclampsia families identifies novel candidate susceptibility genes

OBJECTIVE

Preeclampsia is a common and serious heritable disorder of human pregnancy. Although there have been notable successes in identification of maternal susceptibility genes a large proportion of the heritability of preeclampsia remains unaccounted for. It is has been postulated that rare variation may account for some of this missing heritability. In this study, we performed whole-exome sequencing (WES) in multiplex families to identify rare exonic risk variants.

METHODS

We conducted WES in 244 individuals from 34 Australian/New Zealand multiplex preeclampsia families. Variants were tested for association with preeclampsia using a threshold model and logistic regression.

RESULTS

We found significant association for two moderately rare missense variants, rs145743393 (Padj = 0.0032, minor allele frequency = 0.016) in the chromosome 1 open reading frame 35 (C1orf35) gene, and rs34270076 (Padj = 0.0128, minor allele frequency = 0.024) in the pyroglutamylated RFamide peptide receptor (QRFPR) gene. To replicate these associations we performed imputation in our Australian genome wide association scan for preeclampsia and found no significant exonic variants in either C1orf35 or QRFPR. However, 11 variants demonstrating nominal significance (P < 0.05) in the genomic region between QRFPR and annexin A5 (ANXA5) were identified. We further leveraged publicly available genome-wide available summary data from the UK Biobank to investigate association of these two variants with the underlying clinical phenotypes of preeclampsia and detected nominal association of the QRFPR variant (rs34270076, P = 0.03) with protein levels in females.

CONCLUSION

The study represents the first to use WES in multiplex families for preeclampsia and identifies two novel genes (QRFPR and C1orf35) not previously associated with preeclampsia and find nominal association of rs34270076 with protein levels, a key clinical feature of preeclampsia. We find further support for ANXA5 previously associated with pregnancy complications, including preeclampsia.

Exploring the Molecular Aetiology of Preeclampsia by Massive Parallel Sequencing of DNA

PURPOSE OF REVIEW

This manuscript aims to review (for the first time) studies describing NGS sequencing of preeclampsia (PE) women's DNA.

RECENT FINDINGS

Describing markers for the early detection of PE is an essential task because, although associated molecular dysfunction begins early on during pregnancy, the disease's clinical signs usually appear late in pregnancy. Although several biochemical biomarkers have been proposed, their use in clinical environments is still limited, thereby encouraging research into PE's genetic origin. Hundreds of genes involved in numerous implantation- and placentation-related biological processes may be coherent candidates for PE aetiology. Next-generation sequencing (NGS) offers new technical possibilities for PE studying, as it enables large genomic regions to be analysed at affordable cost. This technique has facilitated the description of genes contributing to the molecular origin of a significant amount of monogenic and complex diseases. Regarding PE, NGS of DNA has been used in familial and isolated cases, thereby enabling new genes potentially related to the phenotype to be proposed. For a better understanding of NGS, technical aspects, applications and limitations are presented initially. Thereafter, NGS studies of DNA in familial and non-familial cases are described, including pitfalls and positive findings. The information given here should enable scientists and clinicians to analyse and design new studies permitting the identification of novel clinically useful molecular PE markers.

Different Polymorphisms of Vascular Endothelial Growth Factor Gene in Patients with Pre-Eclampsia among The Iranian Women Population

Background

Pre-eclampsia (PE) is a pregnancy complication and one of the leading causes of maternal and neonatal morbidity and mortality in the world. PE is characterized by high blood pressure and signs of damage to the other organs, most often the liver and kidneys. Given the importance of mutation in the vascular endothelial growth factor (VEGF) gene and its correlation with the incidence of PE, the relationship of VEGF encoding gene polymorphisms rs922583280, rs3025040 and rs10434 with the incidence of PE in the population of Iranian women was studied, in this research.

Materials and Methods

In this case-control study, 100 pregnant women with PE diagnosis and 50 healthy pregnant women were evaluated using Sanger sequencing method to determine genotypes rs922583280, rs3025040 and rs10434.

Results

There was no significant difference in the allele frequency of rs922583280 and rs3025040 polymorphisms between case and control groups (P>0.05), while frequency of the recessive allele (G) for rs10434 polymorphism was significantly higher in the case group compared to the control group (P=0.014, case=24%, control=12%). Frequency of the allele A in the control group was higher than the patient group (case=76%, control=88%). Frequency of AG genotype in the patient group was also higher than the control group. In addition, frequency of AA genotype in the control group was higher than the patient group (case=57%, control=78).

Conclusion

The results of this study demonstrated a significant difference between patient and control groups for the VEGF coding gene polymorphism rs10434 and it can affect the incidence of PE among Iranian women.

The effect of GPx-1 rs1050450 and MnSOD rs4880 polymorphisms on PE susceptibility: a case- control study

Preeclampsia (PE) is a serious pregnancy complication whose etiology is not fully understood. However, previous reports have suggested that oxidative stress and genetic variants may contribute to the development of PE. This study aimed to examine the relationship between the Glutathione peroxidase-1(GPx-1) and Manganese Superoxide dismutase (MnSOD) polymorphisms and preeclampsia (PE) risk in Iranian women. Genotyping of the studied women, including 179 preeclamptic cases and 202 controls, for GPx-1 rs1050450 and MnSOD rs4880 polymorphisms was conducted using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Our results showed a 1.7- to 1.6-fold increased risk of PE in the rs1050450 CT and CT + TT (dominant model) genotypes compared to CC genotype (OR = 1.7, 95%CI 1.1-2.7; P = 0.01 and OR = 1.6, 95%CI 1.1-2.4; P = 0.02; respectively). We also found a marked correlation between TC and CC genotypes of MnSOD rs4880 polymorphism and a 1.9- to 2.3-fold increase risk of PE (OR = 1.9, 95%CI 1.2-2.9; P = 0.005 and OR = 2.3, 95%CI 1-5.1; P = 0.04, respectively). The rs4880 MnSOD polymorphism was correlated with increased risk of PE in the allelic and dominant models (OR = 1.8, 95% CI 1.2-2.5, P = 0.002; OR = 1.9, 95%CI 1.3-3, P = 0.002, respectively). High frequency of TC/CC genotype of MnSOD rs4880 and CT genotypes of rs1050450 polymorphism in PE patients compared to controls showed the contribution of these variants to PE susceptibility.

Preeclampsia: A close look at renal dysfunction

Preeclampsia (PE) is a unique pathophysiologic situation that physiologic interests of mother, fetus, and placenta diverge. PE is related to the increased circulating antiangiogenic factors originated from hypoxic placenta. It is simply defined by the new onset of hypertension (≥140/90 mmHg) and proteinuria (≥0.3 g/day) after 20 weeks of gestation. PE is associated with kidney dysfunction due to deficiency in podocyte specific vascular endothelial growth factor (VEGF). Hypoxic placenta in PE patients produces increased levels of fms-like tyrosine kinase 1(sFlt-1), a soluble receptor of VEGF. sFlt-1 abrogates binding of VEGF to its receptor on endothelial cells and podocytes, and ultimately damages the filtration barrier. Glomerular endotheliosis and thrombotic microangiopathy (TMA) are the main features of kidney involvement in PE and can induce clotting and vessel occlusion. This complex pathophysiology is ameliorated after delivery; however, permanent kidney damages may remain and is intensified thereafter. This review aims to highlight the biochemical, genetic, and immunological-involved factors in the initiation of PE and explores the relationship between the kidney and PE. This work mainly discusses the pathologic mechanisms of kidney involvement in PE through the lens of the imbalanced VEGF-VEGF receptor signaling pathway.