Association of pre-eclampsia with SOD2 Ala16Val polymorphism among mother-father-infant triads

A method for finding epistatic effects of maternal and fetal variants

Introduction

Pregnancy involves a double genome, and genetic variants in the mother and her fetus can act together to influence risk for pregnancy complications, adverse pregnancy outcomes, and diseases in the offspring. Large search spaces have hindered the discovery of sets of single nucleotide polymorphisms (SNPs) that act epistatically.

Methods

Previously, we proposed a method for case-parent studies, called the Genetic Algorithm for Detecting Genetic Epistasis using Triads or Siblings (GADGETS), that can reveal autosomal epistatic SNP-sets in the child's genome. Here we incorporate maternal SNPs, thereby extending GADGETS to nominate SNP-sets containing offspring loci only, maternal loci only, or both. We use a permutation procedure to impose a preference for epistatic over outcome-related but non-epistatic SNP sets. Our maternal-fetal extension uses case-complement-sibling pairs together with mother-father pairs, exploiting Mendelian transmission and a mating-symmetry assumption.

Results

In simulations of 1,000 case-parents triads with 10,000 candidate SNPs, GADGETS successfully detected simulated multi-locus effects involving 3-5 SNPs but was somewhat less successful at distinguishing epistatic SNPs from sets of non-epistatic SNPs that each conferred high risk independently. Though the epistasis-mining algorithms MDR-PDT, TrioFS, and EPISFA-LD were originally designed to find epistatic offspring variants, we generalize them to include maternal SNPs and search more broadly. GADGETS outperformed those competitors and could successfully mine a much larger list of candidate SNPs. Applied to dbGaP data, GADGETS nominated several multi-SNP maternal-fetal sets as potentially-interacting risk factors for orofacial clefting.

Discussion

The extended version of GADGETS can mine for epistasis that involves maternal SNPs.

Association between Maternal and Fetal Genetic Variants and Preeclampsia: Evidence from a Meta-Analysis

The objective of this meta-analysis was to evaluate the association between maternal and fetal genetic variants and the risk of preeclampsia, a pregnancy-related condition that affects women. Despite the unclear role of these genetic factors in the development of preeclampsia, this analysis aimed to provide insights into the potential contributing factors. An electronic search of online databases was conducted to identify relevant studies. Stata SE software was used for the meta-analysis. A random-effects model was used to establish the association between the genetic variants and preeclampsia risk. Egger's test was utilized to evaluate publication bias. Ten observational studies were selected from databases that met the inclusion criteria and included seven genes and twenty polymorphisms to analyze preeclampsia susceptibility influenced by the genetic background of both the mother and fetus. Our meta-analysis revealed that both the maternal and fetal polymorphisms, FLT1 rs4769613, were significantly associated with the risk of preeclampsia. However, the association between the maternal ACE rs4646994 polymorphism and preeclampsia risk was not statistically significant. Nevertheless, a significant association was observed between the fetal ACE rs4646994 polymorphism and preeclampsia in a dominant genetic model. In this study, the associations between maternal and fetal polymorphisms in ERAP2, VEGF, VDR, REN, and MMP were not statistically significant. According to the available evidence, maternal and fetal polymorphisms can impact the likelihood of developing preeclampsia. Additional research is required to fully understand the underlying mechanisms connecting maternal and fetal polymorphisms to preeclampsia, and to formulate recommendations for screening pregnant women based on these genetic variations.

Modulation of NRF2/KEAP1 Signaling in Preeclampsia

Placentation is a key and tightly regulated process that ensures the normal development of the placenta and fetal growth. Preeclampsia (PE) is a hypertensive pregnancy-related disorder involving about 5-8% of all pregnancies and clinically characterized by de novo maternal hypertension and proteinuria. In addition, PE pregnancies are also characterized by increased oxidative stress and inflammation. The NRF2/KEAP1 signaling pathway plays an important role in protecting cells against oxidative damage due to increased reactive oxygen species (ROS) levels. ROS activate NRF2, allowing its binding to the antioxidant response element (ARE) region present in the promoter of several antioxidant genes such as heme oxygenase, catalase, glutathione peroxidase and superoxide dismutase that neutralize ROS, protecting cells against oxidative stress damages. In this review, we analyze the current literature regarding the role of the NRF2/KEAP1 pathway in preeclamptic pregnancies, discussing the main cellular modulators of this pathway. Moreover, we also discuss the main natural and synthetic compounds that can regulate this pathway in in vivo and in vitro models.

Susceptibility to preeclampsia is associated with a 50-bp insertion/deletion polymorphism at the promoter region of the SOD1 gene

OBJECTIVE

There is much evidence that oxidative stress is involved in the pathogenesis of preeclampsia (PE). A 50 bp insertion/deletion (Ins/Del) functional polymorphism in the promoter region of SOD1 has been reported. Due to a total lack of data, the aim of this study was to investigate the association between the SOD1 (Ins/Del) polymorphism and the risk of PE.

MATERIAL AND METHODS

The current hospital-based case-control study included a total of 172 preeclamptic and 171 non-preeclamptic pregnancies. Genotyping was performed using the polymerase chain reaction method.

RESULTS

Statistical analysis revealed that the Del/Del genotype significantly correlated with susceptibility to PE [odds ratio (OR): 6.53, 95% confidence interval (CI): 1.43-29.7, p=0.015]. Since maternal body mass index, family history of PE in first degree relatives, and educational levels were statistically associated with the susceptibility to PE, further analyses were carried out in order to estimate the adjusted ORs. After adjustment for aforementioned variables, the Del/Del genotype increased the risk of PE (OR: 5.98, 95% CI: 1.21-29.5, p=0.028).

CONCLUSION

The 50 bp Ins/Del in promoter region of the SOD1 gene could be an intriguing susceptibility factor for developing preeclampsia in Iranian Caucasians.

Association of CYBA C242T and superoxide dismutase 2 A16V genetic variants with preeclampsia

OBJECTIVE

To investigate the relationship between NADPH oxidase p22phox subunit (CYBA; C242T) and superoxide dismutase 2 (SOD2; A16V) polymorphisms and the risk of preeclampsia (PE) in Chinese women.

METHODS

This case-control study included 325 patients with PE and 1294 controls. The genotypes were determined by polymerase chain reaction-restriction fragments length polymorphism method. Clinical, metabolic, and oxidative stress parameters were analyzed.

RESULTS

Participants with T allele of the CYBA C242T polymorphism had a decreased risk of PE (OR = 0.62, 95% CI: 0.42-0.92, P = 0.016) and those with the A allele of the SOD2 A16V polymorphism had increased risk of PE (OR = 1.44, 95% CI: 1.09-1.89, P = 0.010). The coexistence of the SOD2 AA + AV genotypes and the CYBA CC genotype further increased the risk of PE (OR = 2.32, 95% CI: 1.31-4.10, P = 0.003) when the CT + TT/VV combined genotype was the reference category.

CONCLUSION

The T allele of the CYBA C242T polymorphism is related to a decreased risk of PE, while the A allele of the SOD2 A16V polymorphism and its combination with the CYBA CC genotype are associated with an increased risk of PE in Chinese women.

Oxidative stress-related genes (EPHX1 and MnSOD) polymorphism and risk of pre-eclampsia: a meta-analysis

BACKGROUND

Previous studies have detected the association of polymorphisms in oxidative stress-related genes EPHX1 and MnSOD with pre-eclampsia (PE) risk, but the results are inconsistent among studies. Thus, a meta-analysis was performed to obtain more conclusive results.

METHODS

Eligible studies were retrieved in PubMed, Web of Science, EMBASE, Scopus, and CNKI. Odds ratios (ORs) with 95% confidence intervals (CIs) were utilized to evaluate the relationship between EPHX1 rs1051740, EPHX1 rs2234922, MnSOD rs4880 polymorphisms, and PE susceptibility in the genetic models. The subgroup analysis was also performed.

RESULTS

Fourteen studies with a total of 4250 participants were included, including 1784 PE patients and 2466 healthy women. There was a statistically significant association between EPHX1 rs1051740 polymorphism and PE in Caucasians within the allele, dominant, heterozygous, and homozygous models (OR = 0.79, 95% CI = 0.64-0.98; OR = 0.64, 95% CI = 0.47-0.87; OR = 0.61, 95% CI = 0.44-0.85; OR = 0.63, 95% CI = 0.42-0.97, respectively). There was a statistically significant association between EPHX1 rs2234922 polymorphism and PE in Middle Easterners within the recessive and homozygous models (OR = 3.59, 95% CI = 1.25-10.32; OR = 3.99, 95% CI = 1.38-11.49, respectively). There was no statistically significant association between MnSOD rs4880 polymorphism and PE within five genetic models. Subgroup analysis didn't reveal any association between MnSOD rs4880 polymorphism and PE in Asians, Caucasians, or Middle Easterners.

CONCLUSIONS

This meta-analysis shows a significant association between the EPHX1 rs1051740 and PE risk in Caucasians. Meantime, there was a statistically significant association between EPHX1 rs2234922 polymorphism and PE in Middle Easterners.

Riding the tiger - physiological and pathological effects of superoxide and hydrogen peroxide generated in the mitochondrial matrix

Elevated mitochondrial matrix superoxide and/or hydrogen peroxide concentrations drive a wide range of physiological responses and pathologies. Concentrations of superoxide and hydrogen peroxide in the mitochondrial matrix are set mainly by rates of production, the activities of superoxide dismutase-2 (SOD2) and peroxiredoxin-3 (PRDX3), and by diffusion of hydrogen peroxide to the cytosol. These considerations can be used to generate criteria for assessing whether changes in matrix superoxide or hydrogen peroxide are both necessary and sufficient to drive redox signaling and pathology: is a phenotype affected by suppressing superoxide and hydrogen peroxide production; by manipulating the levels of SOD2, PRDX3 or mitochondria-targeted catalase; and by adding mitochondria-targeted SOD/catalase mimetics or mitochondria-targeted antioxidants? Is the pathology associated with variants in SOD2 and PRDX3 genes? Filtering the large literature on mitochondrial redox signaling using these criteria highlights considerable evidence that mitochondrial superoxide and hydrogen peroxide drive physiological responses involved in cellular stress management, including apoptosis, autophagy, propagation of endoplasmic reticulum stress, cellular senescence, HIF1α signaling, and immune responses. They also affect cell proliferation, migration, differentiation, and the cell cycle. Filtering the huge literature on pathologies highlights strong experimental evidence that 30-40 pathologies may be driven by mitochondrial matrix superoxide or hydrogen peroxide. These can be grouped into overlapping and interacting categories: metabolic, cardiovascular, inflammatory, and neurological diseases; cancer; ischemia/reperfusion injury; aging and its diseases; external insults, and genetic diseases. Understanding the involvement of mitochondrial matrix superoxide and hydrogen peroxide concentrations in these diseases can facilitate the rational development of appropriate therapies.

Nutrigenetics of antioxidant enzymes and micronutrient needs in the context of viral infections

Sustaining adequate nutritional needs of a population is a challenging task in normal times and a priority in times of crisis. There is no 'one-size-fits-all' solution that addresses nutrition. In relevance to the COVID-19 (coronavirus disease 2019) pandemic crisis, viral infections in general and RNA viruses in particular are known to induce and promote oxidative stress, consequently increasing the body's demand for micronutrients, especially those related to antioxidant enzymic systems, thus draining the body of micronutrients, and so hindering the human body's ability to cope optimally with oxidative stress. Common polymorphisms in major antioxidant enzymes, with world population minor allele frequencies ranging from 0·5 to 50 %, are related to altered enzymic function, with substantial potential effects on the body's ability to cope with viral infection-induced oxidative stress. In this review we highlight common SNP of the major antioxidant enzymes relevant to nutritional components in the context of viral infections, namely: superoxide dismutases, glutathione peroxidases and catalase. We delineate functional polymorphisms in several human antioxidant enzymes that require, especially during a viral crisis, adequate and potentially additional nutritional support to cope with the pathological consequences of disease. Thus, in face of the COVID-19 pandemic, nutrition should be tightly monitored and possibly supplemented, with special attention to those carrying common polymorphisms in antioxidant enzymes.

Paternal Determinants in Preeclampsia

Preeclampsia is a condition associated with high rates of maternal-fetal morbidity and mortality. It usually occurs in 3–10% of nulliparous women and 18% of previously affected women. Different lines of evidence have demonstrated the role of the father in the onset of preeclampsia. The placenta is the cornerstone of preeclampsia and poses important paternal genetic determinants; in fact, the existence of a “paternal antigen” has been proposed. Nulliparity is a well-known risk factor. Change of partner to a woman without history of preeclampsia increases the risk; however, this change decreases in women with history of the condition. High interval between pregnancies, short sexual intercourse before pregnancy, and conception by intracytoplasmic sperm injection suggest a limited exposure to the so-called paternal antigen. A man who was born from a mother with preeclampsia also increases the risk to his partner. Not only maternal but also paternal obesity is a risk factor for preeclampsia. Fetal HLA-G variants from the father increased the immune incompatibility with the mother and are also significantly associated with preeclampsia in multigravida pregnancies. An analysis of a group of Swedish pregnant women showed that the risk for preeclampsia is attributable to paternal factors in 13% of cases, which could be related to genetic interactions with maternal genetic factors. This review aimed to evaluate the evidences of the father’s contribution to the onset of preeclampsia and determine the importance of including them in future studies.

Peripartum Cardiomyopathy and Preeclampsia: Overlapping Diseases of Pregnancy

PURPOSE OF REVIEW

Hypertensive disorders of pregnancy (HDP) often result in cardiac dysfunction and have been variably included as a risk factor for peripartum cardiomyopathy (PPCM). However, there is debate regarding the relationship between the two entities.

RECENT FINDINGS

Diastolic dysfunction appears to be more predominant among gravidas with HDP, while systolic dysfunction predominates in PPCM. However, this finding is not consistent in all studies. Recent examinations of mortality and morbidity associated with PPCM in the setting of HDP do not demonstrate a predominant pattern with a mixture of results. Further, right ventricular dysfunction is identified to be a common theme in both populations. From a basic science perspective, there is evidence to demonstrate a predominantly anti-angiogenic milieu in both PPCM and HDP. PPCM and HDP associated cardiomyopathy overlap significantly. As such, unifying theories for their pathophysiology should be investigated.