Analysis of polymorphisms in interleukin-10, interleukin-6, and interleukin-1 receptor antagonist in Mexican-Mestizo women with pre-eclampsia

A review of key cytokines based on gene polymorphism in the pathogenesis of pre-eclampsia

Although a number of theories have been suggested, including roles for oxidative stress, an abnormal maternal-fetal interface, and genetic and environmental factors, the etiopathology of pre-eclampsia (PE) remains unclear. Maternal immune tolerance is important for maintaining pregnancy, and researchers have increasingly focused on the critical roles of cytokines in the pathogenesis of PE in recent years. The assessment of candidate genetic polymorphisms in PE could partially elucidate the mechanisms of susceptibility to disease, and contribute to seeking for new diagnosis and treatment methods of PE. PE can lead to severe complications, and even the death of both mother and fetus. Although the complex pathology is not yet clear, some evidence suggested that the occurrence of PE is related to inflammatory factors. We reviewed the current understandings of roles of cytokines in PE, and provided an extensive overview of the role of single nucleotide chain polymorphisms (SNPs) in the genes potentially underlying the pathophysiology of PE.

Are genetic variations in IL-1β and IL-6 cytokines associated with the risk of pre-eclampsia? Evidence from a systematic review and meta-analysis

OBJECTIVE

This systematic review and meta-analysis study was performed to assess the potential association between interleukin-1 beta (IL-1β) single nucleotide polymorphisms (SNPs) (rs1143634 and rs16944) and interleukin-6 (IL-6) SNP (rs1800795) and pre-eclampsia (PE).

METHODS

A comprehensive literature search was conducted in the international search engines and databases, including MEDLINE (via PubMed), Scopus, and Web of Science (ISI) up to 9 March 2021. After retrieving relevant articles, data extraction was performed by four authors independently. Pooled ORs and corresponding 95% CIs were used to evaluate the association between IL-1β and IL-6 polymorphisms and PE risk. Cochran's Q test was used to check heterogeneity, and the I² index was calculated for measuring the heterogeneity between the estimations of included studies.

RESULTS

After reviewing fully published studies, 21 studies were included in this study based on the eligibility criteria. Our results showed that rs16944 and rs1143634 of IL-1β were significantly associated with the risk of PE. Regarding rs16944, the minor C allele significantly decreased the risk of PE (C vs. T: OR = 0.79, 95% CI = 0.69-0.90). In contrast, the minor T allele of rs1143634 significantly increased the risk of PE (T vs. C: OR = 1. 28, 95% CI = 1.04-1.58). There was no significant association between IL-6 rs1800795 (C vs. G: OR = 1.04, 95% CI = 0.93-1.16) polymorphism and PE risk.

CONCLUSIONS

In conclusion, this meta-analysis suggests rs1143634 and rs16944 polymorphisms of IL-1β are related to the risk of PE.

Genetic markers for preeclampsia in Peruvian women

BACKGROUND

Preeclampsia is a multiorgan disorder associated with maternal and perinatal morbi-mortality. In Peru, incidence is 10% and accounts for 22% of maternal deaths. Genome and genetic epidemiological studies have found an association between preeclampsia and genetic polymorphisms.

OBJECTIVE

To determine the association of the vascular endothelial growth factor (VEGF) +936 C/T and +405 G/C, interleukine-6 (IL-6) -174 G/C, IL-1β-511 C/T, Apo A-1-75 G/A, Apo B-100 2488 C/T (Xbal) polymorphisms with preeclampsia in pregnant Peruvian women.

METHODS

Were included preeclamptic and healthy (control) pregnant women. Maternal blood samples were subjected to DNA extraction, and molecular genetic analysis was conducted using the PCR-RFLP technique and following a specific protocol for each gene. Allele and genotypic frequencies in the cases and controls were compared.

RESULTS

No association was found between the VEGF+936C/T and VEGF+405 polymorphisms and preeclampsia. The frequencies of the GG genotypes and the G allele of the -174 G/C polymorphism in the IL6 gene in preeclamptic and controls showed significant differences, with higher frequencies in cases. For the -511 C/T polymorphism of the IL-1β gene, no significant differences were found in the frequencies of TT genotypes compared with CT+CC. The genotypes and alleles of the Apo-A1-75 G/A and Apo-B100 Xbal variants showed no significant differences between cases and controls.

CONCLUSION

No association was found between the studied genetic markers and preeclampsia. However, in the -174G/C polymorphism of the IL-6 gene, significant differences were found mainly in the GG genotype and G allele.

Association of Interleukin-10 -1082G > A Polymorphism with Susceptibility to Preeclampsia: A Systematic Review and Meta-Analysis Based on 21 Studies

Background: Previous studies have reported the association between IL-10 -1082 G > A polymorphism and preeclampsia risk, but the results remained controversial. Therefore, this meta-analysis was performed to evaluate the association of IL-10 -1082 G > A polymorphism with preeclampsia risk.Methods: We searched PubMed, ISI Web of Knowledge and CNKI databases to identify eligible studies up to September 05, 2019.Results: A total of 21 case-control studies with 3,510 cases and 5,874 controls were selected. The results revealed that IL-10 -1082 G > A polymorphism was significantly associated with an increased risk of preeclampsia under the recessive model (AA vs. AG + GG: OR = 1.191, 95% CI = 1.018-1.394, P = 0.029). Stratified analyses by ethnicity revealed a significantly increased risk of preeclampsia in Asian and mixed populations, but not in Caucasians. Moreover, there was a significant association among Chinese and Brazilian.Conclusions: Our results showed that IL-10 -1082 G > A polymorphism was significantly associated with an increased risk of preeclampsia.

Association of IL-6 -176G > C Polymorphism with Susceptibility to Preeclampsia: A Systematic Review and Meta-Analysis

Background: Many studies have described the influence of -176G > C polymorphism of the IL-6 gene on susceptibility to preeclampsia. However, the results have remained inconclusive and controversial. Therefore, we performed a meta-analysis to more precisely determine the association between the IL-6 -176G > C polymorphism and preeclampsia risk. Methods: Electronic databases including PubMed, Embase, Web of Science, and CNKI were searched up to August 15, 2019. The pooled odds ratios (ORs) and their corresponding 95% confidence intervals (CIs) were used to calculate the association. Results: A total of 12 studies with 1,821 preeclampsia cases and 3,339 controls were selected. Overall, no significant association was found between IL-6 -176G > C polymorphism and preeclampsia risk. In the stratified analyses by ethnicity, there was a significant association in Asians, but not in Caucasians and mixed populations. Conclusions: The results of meta-analysis indicated that IL-6 -176G > C polymorphism was not significantly associated with risk of preeclampsia in overall population.

The role of the IL-1 system in pregnancy and the use of IL-1 system markers to identify women at risk for pregnancy complications†

The interleukin (IL)-1 system plays a major role in immune responses and inflammation. The IL-1 system components include IL-1α, IL-1β, IL-1 receptor type 1 and IL-1 receptor type 2 (decoy receptor), IL-1 receptor accessory protein, and IL-1 receptor antagonist (IL-1Ra). These components have been shown to play a role in pregnancy, specifically in embryo-maternal communication for implantation, placenta development, and protection against infections. As gestation advances, maternal tissues experience increasing fetal demand and physical stress and IL-1β is induced. Dependent on the levels of IL-1Ra, which regulates IL-1β activity, a pro-inflammatory response may or may not occur. If there is an inflammatory response, prostaglandins are synthesized that may lead to myometrial contractions and the initiation of labor. Many studies have examined the role of the IL-1 system in pregnancy by independently measuring plasma, cervical, and amniotic fluid IL-1β or IL-1Ra levels. Other studies have tested for polymorphisms in IL-1β and IL-1Ra genes in women experiencing pregnancy complications such as early pregnancy loss, in vitro fertilization failure, pre-eclampsia and preterm delivery. Data from those studies suggest a definite role for the IL-1 system in successful pregnancy outcomes. However, as anticipated, the results varied among different experimental models, ethnicities, and disease states. Here, we review the current literature and propose that measurement of IL-1Ra in relation to IL-1 may be useful in predicting the risk of poor pregnancy outcomes.

Genetic Variants in Preeclampsia: Lessons From Studies in Latin-American Populations

Placental vascularization is a tightly regulated physiological process in which the maternal immune system plays a fundamental role. Vascularization of the maternal-placental interface involves a wide range of mechanisms primarily orchestrated by the fetal extravillous trophoblast and maternal immune cells. In a healthy pregnancy, an immune cross-talk between the mother and fetal cells results in the secretion of immunomodulatory mediators, apoptosis of specific cells, cellular differentiation/proliferation, angiogenesis, and vasculogenesis, altogether favoring a suitable microenvironment for the developing embryo. In the context of vasculopathy underlying common pregnancy disorders, it is believed that inefficient invasion of extravillous trophoblast cells in the endometrium leads to a poor placental blood supply, which, in turn, leads to decreased secretion of angiogenic factors, hypoxia, and inflammation commonly associated with preterm delivery, intrauterine growth restriction, and preeclampsia. In this review, we will focus on studies published by Latin American research groups, providing an extensive review of the role of genetic variants from candidate genes involved in a broad spectrum of biological processes underlying the pathophysiology of preeclampsia. In addition, we will discuss how these studies contribute to fill gaps in the current understanding of preeclampsia. Finally, we discuss some trending topics from important fields associated with pregnancy vascular disorders (e.g., epigenetics, transplantation biology, and non-coding RNAs) and underscore their possible implications in the pathophysiology of preeclampsia. As a result, these efforts are expected to give an overview of the extent of scientific research produced in Latin America and encourage multicentric collaborations by highlighted regional research groups involved in preeclampsia investigation.

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.

Combination of Genetic Markers and Age Effectively Facilitates the Identification of People with High Risk of Preeclampsia in the Han Chinese Population

Objective

This study aimed to analyze the possible association between known genetic risks and preeclampsia in a Han Chinese population.

Methods

A total of 156 patients with preeclampsia and 286 healthy Han Chinese women were enrolled and genotyped for 27 genetic alleles associated with preeclampsia in different populations. The association between the genotypes of the individual alleles and preeclampsia and the possible interaction among the alleles were analyzed. Finally logistic models were trained with the genotypes of possible alleles contributing to preeclampsia.

Results

Seven alleles were significantly or marginally significantly associated with preeclampsia, which involved six genes (rs4762 in AGT, rs1800896 in IL-10, rs1800629 and rs1799724 in TNFα, rs2070744 in NOS3, rs7412 in APOE, and rs2549782 in ERAP2). A multilocus interaction analysis further disclosed an interaction among seven alleles. A logistic model showing individual or synergetic contribution to preeclampsia could reach ~0.67 preeclampsia prediction accuracy in the Han Chinese population, while integration of age information could improve the performance to ~0.75 accuracy using a fivefold training-testing evaluation strategy.

Conclusions

The genetic factors were closely associated with preeclampsia in the Han Chinese population despite large ethnicity heterogeneity. The genotypes of different alleles also had synergetic interactions.

Interleukin-10 rs1800871 (-819C/T) and ATA haplotype are associated with preeclampsia in a Tunisian population

OBJECTIVES

Interleukin-10 (IL-10) is implicated in several aspects of pregnancy. As genetic predisposition can be involved in the development of preeclampsia, the association between IL-10's promoter region polymorphisms and this pathology has been investigated, although with conflicting results. To date, only a small cohort study (total n = 40) has evaluated this association in the African continent, and none have been conducted in Tunisia. Hence, we evaluated the association between these polymorphisms and the risk of preeclampsia in a large Tunisian cohort.

STUDY DESIGN

345 preeclampsia patients and 300 controls were genotyped for the IL-10 promoter region variants -1082A/G, -819C/T and -592A/C using real-time PCR.

MAIN OUTCOME MEASURES

Differences in means were determined by Student's t-test, while intergroup significance was assessed by Pearson χ² or 2-way ANOVA. Genotypes were tested for Hardy-Weinberg equilibrium (HWE) in the control and cases. Logistic regression analysis was performed in order to determine the odds ratios and 95% confidence intervals associated with the linkage disequilibrium risk.

RESULTS

An increased frequency of the -819 T (minor) allele and the -819 T/T genotype was seen in preeclampsia cases. Also, three-locus haplotype (-1082AG/-819CT/-592AC) analysis identified the ATA haplotype as having a higher incidence in women with preeclampsia (OR = 1.48, 95% CI: 1.03-2.11) and this was confirmed by multivariate regression analysis (OR = 1.65, 95% CI: 1.13-2.43) after controlling for covariates.

CONCLUSIONS

We suggest that the IL-10 -819 T/T variant and the ATA haplotype, which are associated with low production of IL 10, represent genetic risk factors for preeclampsia in Tunisian women.

Polymorphisms in Inflammatory Mediator Genes and Risk of Preeclampsia in Taiyuan, China

Excessive maternal inflammatory response is involved in the pathogenesis of preeclampsia. Few epidemiologic studies have investigated the associations between genetic variations in the inflammatory mediator genes and preeclampsia risk, and these studies have reached inconsistent results. We examined 31 single-nucleotide polymorphisms in IL-1A, IL-1B, IL-1R1, IL-2RA, IL-5RA, IL-6, IL-6R, TNFSF11, TNFRSF11A, IL-28RA, IRAK4, and KIT genes and the risk of preeclampsia and its clinical subtypes in a nested case-control study including 203 preeclampsia cases and 233 controls. We found that IL-1R1, IL-5RA, IL-6R, and TNFSF11 were associated with the risk of preeclampsia. Although the significant associations observed for preeclampsia overall were mainly seen for late-onset preeclampsia and severe preeclampsia, IL-6R (rs2229238) and TNFSF11 (rs9525643) polymorphisms were associated with the risk of early-onset preeclampsia. TNFSF11 (rs2200287 and rs2148072) polymorphisms were associated with risk of mild preeclampsia. Our study provided the first evidence that genetic variations in inflammatory mediator genes IL-1R1, IL-6R, TNFSF11, and IL-5RA were associated with preeclampsia risk, and the risk varied by preeclampsia subtypes.

ETHNICITY AND INCOME IMPACT ON BMI AND STATURE OF SCHOOL CHILDREN LIVING IN URBAN SOUTHERN MEXICO

Obesity affects quality of life and increases the risk of morbidity and mortality. Mexico, a middle-income country, has a high prevalence of overweight and obesity among urban children. Merida is the most populated and growing city in southern Mexico with a mixed Mayan and non-Maya population. Local urbanization and access to industrialized foods have impacted the eating habits and physical activity of children, increasing the risk of overweight and obesity. This study aimed to contribute to the existing literature on the global prevalence of overweight and obesity and examined the association of parental income, ethnicity and nutritional status with body mass index (BMI) and height in primary school children in Merida. The heights and weights of 3243 children aged 6-12 from sixteen randomly selected schools in the city were collected between April and December 2012. Multinomial logistic regression models were used to examine differences in the prevalence of BMI and height categories (based on WHO reference values) by ethnicity and income levels. Of the total students, 1648 (50.9%) were overweight or obese. Stunting was found in 227 children (7%), while 755 (23.3%) were defined as having short stature. Combined stunting and overweight/obesity was found in 301 students (9.3%) and twelve (0.4%) were classified as stunted and of low weight. Having two Mayan surnames was inversely associated with having adequate height (OR=0.69, p<0.05) and the presence of two Maya surnames in children increased the odds of short stature and stunting. Children from lower income families had twice the odds of being stunted and obese. Overweight, obesity and short stature were frequent among the studied children. A significant proportion of Meridan children could face an increased risk of developing cardiovascular disease and its associated negative economic and social outcomes unless healthier habits are adopted. Action is needed to reduce the prevalence of obesity among southern Mexican families of all ethnic groups, particularly those of lower income.

Role of IL-6 -174(G/C) promoter polymorphism in the etiology of early-onset preeclampsia

OBJECTIVE

To investigate the relationship between IL-6 -174G/C promoter polymorphism and preeclampsia.

METHODS

A total of 140 preeclamptic women and 135 women with normal pregnancy were considered for the present study. A standard amplification refractory mutation system PCR was carried out for genotyping of IL-6 G-174C promoter polymorphism. Genotypic distribution was compared with values predicted by Hardy-Weinberg equilibrium using χ (2) test. Odds ratios and their respective 95 % confidence intervals were used to measure the strength of association.

RESULTS

The frequencies observed, CC, GC and GG, were 53.5, 26.6 and 20 % in patients and 26.6, 23.7 and 49.6 % in the controls. There is a significant difference in the distribution of genotypes and alleles of IL-6 G-174 C between the two groups.

CONCLUSION

The present study suggests that the IL-6 -174 promoter polymorphism is a major genetic regulator in the etiology of early-onset preeclampsia.

Evaluation of association of maternal IL-10 polymorphisms with risk of preeclampsia by A meta-analysis

Emerging evidence shows that interleukin (IL)-10 gene polymorphisms can regulate its expression level and thus influence person's susceptibility to preeclampsia. However, various published results were inconsistent. To explore the association between maternal IL-10 gene polymorphisms and preeclampsia, we performed a meta-analysis based upon 11 individual studies here. Our meta-analysis results indicated that IL-10 -819C/T (C versus T, OR = 1.28, 95% CI = 1.08–1.50, P = 0.003) and -592C/A (C versus A, OR = 1.28, 95% CI = 1.03–1.59, P = 0.03) polymorphisms were associated with preeclampsia. Although there was no overall association between -1082A/G polymorphism and preeclampsia (G versus A, OR = 0.93, 95% CI = 0.77–1.13, P = 0.49), such association existed among Asian (G versus A, OR = 1.29, 95% CI = 1.04–1.60, P = 0.02) and South American (G versus A, OR = 0.72, 95% CI = 0.54–0.94, P = 0.02) populations in the subgroup analysis stratified by continents.

Genetic variations in IL1A and IL1RN are associated with the risk of preeclampsia in Chinese Han population

Preeclampsia (PE) is an excessive systemic inflammation response with dysfunction of endothelial. Our study was to investigate the association between genetic variations in IL-1 and the susceptibility to PE in Chinese Han population. 402 PE patients and 554 normal pregnant women of third trimester were enrolled. The polymorphisms of rs315952 in IL1RN and rs17561 in IL1A were genotyped by TaqMan allelic discrimination real-time PCR. Obviously statistic difference of the genotypic frequencies were found in both of IL1RN rs315952 and IL1A rs17561 between cases and controls (for rs315952, P = 0.001; for rs17561, P = 0.021.). For rs315952, the C allele was associated with development of PE (P = 0.003, OR = 1.319, 95%CI 1.099–1.583). Patients with CC or CT genotype were less likely to develop severe PE than patients carrying TT genotype(P< 0.001, OR = 0.24, 95%CI 0.15–0.40). For rs17561, the C allele was the risk factor for predisposition to PE (P = 0.012, OR = 1.496, 95%CI 1.089–2.055). Our results suggest IL1RN and IL1A may involve in the development of PE in Chinese Han population.