Hypoxia-inducible factor-1α gene polymorphisms in early and late onset preeclampsia in Sinhalese women

Hypoxia-Inducible Pathway Polymorphisms and Their Role in the Complications of Prematurity

Excessive oxidative stress resulting from hyperoxia or hypoxia is a recognized risk factor for diseases of prematurity. However, the role of the hypoxia-related pathway in the development of these diseases has not been well studied. Therefore, this study aimed to investigate the association between four functional single nucleotide polymorphisms (SNPs) in the hypoxia-related pathway, and the development of complications of prematurity in relation to perinatal hypoxia. A total of 334 newborns born before or on the 32nd week of gestation were included in the study. The SNPs studied were HIF1A rs11549465 and rs11549467, VEGFA rs2010963, and rs833061. The findings suggest that the HIF1A rs11549465T allele is an independent protective factor against necrotizing enterocolitis (NEC), but may increase the risk of diffuse white matter injury (DWMI) in newborns exposed to hypoxia at birth and long-term oxygen supplementation. In addition, the rs11549467A allele was found to be an independent protective factor against respiratory distress syndrome (RDS). No significant associations with VEGFA SNPs were observed. These findings indicate the potential involvement of the hypoxia-inducible pathway in the pathogenesis of complications of prematurity. Studies with larger sample sizes are needed to confirm these results and explore their clinical implications.

Association of hypoxia inducible factor 1-Alpha gene polymorphisms with multiple disease risks: A comprehensive meta-analysis

HIF1A gene polymorphisms have been confirmed the association with cancer risk through the statistical meta-analysis based on single genetic association (SGA) studies. A good number SGA studies also investigated the association of HIF1A gene with several other diseases, but no researcher yet performed statistical meta-analysis to confirm this association more accurately. Therefore, in this paper, we performed a statistical meta-analysis to draw a consensus decision about the association of HIF1A gene polymorphisms with several diseases except cancers giving the weight on large sample size. This meta-analysis was performed based on 41 SGA study’s findings, where the polymorphisms rs11549465 (1772 C/T) and rs11549467 (1790 G/A) of HIF1A gene were analyzed based on 11544 and 7426 cases and 11494 and 7063 control samples, respectively. Our results showed that the 1772 C/T polymorphism is not significantly associated with overall disease risks. The 1790 G/A polymorphism was significantly associated with overall diseases under recessive model (AA vs. AG + GG), which indicates that the A allele is responsible for overall diseases though it is recessive. The subgroup analysis based on ethnicity showed the significant association of 1772 C/T polymorphism with overall disease for Caucasian population under the all genetic models, which indicates that the C allele controls overall diseases. The ethnicity subgroup showed the significant association of 1790 G/A polymorphism with overall disease for Asian population under the recessive model (AA vs. AG + GG), which indicates that the A allele is responsible for overall diseases. The subgroup analysis based on disease types showed that 1772 C/T is significantly associated with chronic obstructive pulmonary disease (COPD) under two genetic models (C vs. T and CC vs. CT + TT), skin disease under two genetic models (CC vs. TT and CC + CT vs. TT), and diabetic complications under three genetic models (C vs. T, CT vs. TT and CC + CT vs. TT), where C allele is high risk factor for skin disease and diabetic complications (since, ORs > 1), but low risk factor for COPD (since, ORs < 1). Also the 1790 G/A variant significantly associated with the subgroup of cardiovascular disease (CVD) under homozygote model, diabetic complications under allelic and homozygote models, and other disease under four genetic models, where the A is high risk factor for diabetic complications and low risk factor for CVD. Thus, this study provided more evidence that the HIF1A gene is significantly associated with COPD, CVD, skin disease and diabetic complications. These might be the severe comorbidities and risk factors for multiple cancers due to the effect of HIF1A gene and need further investigations accumulating large number of studies.

Association of interleukin-12B gene polymorphisms and mRNA expression with preeclampsia

OBJECTIVE

To explore the effects of functional genetic polymorphisms of the interleukin-12B (IL-12B) gene on the susceptibility to preeclampsia in northern Chinese women.

STUDY DESIGN

Maternal peripheral blood from 306 preeclamptic women and 310 control women and the placentas from 52 preeclamptic and 55 control women were collected. Two polymorphisms (rs17860508 and rs3212227) of the IL-12B gene were genotyped by polymerase chain reaction (PCR) with a direct sequencing method. The mRNA expression of IL-12B in the placentas was measured by quantitative real-time PCR (qRT-PCR).

RESULTS

Significant differences were observed between preeclamptic women and the control group in the genotype frequencies of rs17860508 (P = 0.017). Compared with the TTAGAG/TTAGAG genotype of rs17860508, the GC/GC genotype were associated with a higher risk of preeclampsia (adjusted OR: 1.95; 95% CI = 1.18-3.22; P = 0.009), especially the early-onset preeclampsia (adjusted OR: 2.40; 95% CI = 1.23-4.68; P = 0.010). The qRT-PCR results showed that the mRNA levels of IL-12B were significantly higher in the placentas of preeclampsia patients than that in the placentas of controls (P = 0.001). Moreover, the expression of IL-12B mRNA was significantly higher in the placentas of patients carrying the GC/GC genotype than in those carrying the TTAGAG/GC (P = 0.007) and TTAGAG/TTAGAG (P = 0.005) genotypes.

CONCLUSION

The GC/GC genotype of rs17860508 polymorphism may be a risk factor for the early-onset preeclampsia by upregulating the expression of IL-12B in northern Chinese women.

Prediction of potential deleterious nonsynonymous single nucleotide polymorphisms of HIF1A gene: A computational approach

Hypoxia-inducible factor-1α (HIF-1α) is the oxygen sensitive subunit of HIF1 transcription factor. Its variations is associated with several diseases including different type of cancer, cardiovascular diseases, and liver and kidney failure. Despite all the investigations carried out on the single nucleotide polymorphisms (SNPs) of HIF1A gene and diseases, there are many uncharacterized nonsynonymous SNPs of this gene, which might have damaging effect on the protein function. Therefore, it is worthwhile to analyze these potential damaging nsSNPs, using different bioinformatics tools before launching large population studies. The objective of the present study was to predict the possible deleterious nsSNPs of HIF1A gene and their effects on the function and structure of HIF-1alpha protein, using different bioinformatics tools. Various prediction servers were used including SIFT, PROVEAN, PolyPhen-2, PANTHER, phD-SNP, SNP-GO, I-Mutant 2.0, Fathmm, SNPeffect 4.0, Mutation taster, CADD and RAMPAGE in a stepwise approach. After analyzing all 454 missense variants of the HIF1A gene using the abovementioned tools, we reported 11 variants with a significant impact on the function or structure of HIF-1α protein. Furthermore, among these variants only S274 P was predicted as stability enhancing variant with effect on protein function by increasing its stability. Although there are many advantages for computational analysis, the results has to be confirmed by experimental investigations.

Mechanisms linking exposure to preeclampsia in utero and the risk for cardiovascular disease

Preeclampsia (PE) is now recognised as a cardiovascular risk factor for women. Emerging evidence suggests that children exposed to PE in utero may also be at increased risk of cardiovascular disease (CVD) in later life. Individuals exposed to PE in utero have higher systolic and diastolic blood pressure and higher body mass index (BMI) compared to those not exposed to PE in utero. The aim of this review is to discuss the potential mechanisms driving the relationship between PE and offspring CVD. Exposure to an adverse intrauterine environment as a consequence of the pathophysiological changes that occur during a pregnancy complicated by PE is proposed as one mechanism that programs the fetus for future CVD risk. Consistent with this hypothesis, animal models of PE where progeny have been studied demonstrate causality for programming of offspring cardiovascular health by the preeclamptic environment. Shared alleles between mother and offspring, and shared lifestyle factors between mother and offspring provide alternate pathways explaining associations between PE and offspring CVD risk. In addition, adverse lifestyle habits can also act as second hits for those programmed for increased CVD risk. PE and CVD are both multifactorial diseases and, hence, identifying the relative contribution of PE to offspring risk for CVD is a very complex task. However, considering the emerging strong association between PE and CVD, those exposed to PE in utero may benefit from targeted primary CVD preventive strategies.

Damaging Variants in Proangiogenic Genes Impair Growth in Fetuses with Cardiac Defects

OBJECTIVE

To determine the impact of damaging genetic variation in proangiogenic pathways on placental function, complications of pregnancy, fetal growth, and clinical outcomes in pregnancies with fetal congenital heart defect.

STUDY DESIGN

Families delivering a baby with a congenital heart defect requiring surgical repair in infancy were recruited. The placenta and neonate were weighed and measured. Hemodynamic variables were recorded from a third trimester (36.4 ± 1.7 weeks) fetal echocardiogram. Exome sequencing was performed on the probands (N = 133) and consented parents (114 parent-child trios, and 15 parent-child duos) and the GeneVetter analysis tool used to identify damaging coding sequence variants in 163 genes associated with the positive regulation of angiogenesis (PRA) (GO:0045766).

RESULTS

In total, 117 damaging variants were identified in PRA genes in 133 congenital heart defect probands with 73 subjects having at least 1 variant. Presence of a damaging PRA variant was associated with increased umbilical artery pulsatility index (mean 1.11 with variant vs 1.00 without; P = .01). The presence of a damaging PRA variant was also associated with lower neonatal length and head circumference for age z score at birth (mean -0.44 and -0.47 with variant vs 0.23 and -0.05 without; P = .01 and .04, respectively). During median 3.1 years (IQR 2.0-4.1 years) of follow-up, deaths occurred in 2 of 60 (3.3%) subjects with no PRA variant and in 9 of 73 (12.3%) subjects with 1 or more PRA variants (P = .06).

CONCLUSIONS

Damaging variants in proangiogenic genes may impact placental function and are associated with impaired fetal growth in pregnancies involving a fetus with congenital heart defect.

Genetic polymorphism in DGCR8 is associated with late onset of preeclampsia

Background

PE (preeclampsia) is a heterogeneous disorder with early onset PE (EOPE) and late onset PE (LOPE) subtypes. Associations between maternal miRNAs biosynthesis genes polymorphisms and risk of PE have been previously observed. However, the impact of polymorphisms in DGCR8 which is indispensable in miRNA maturing processing on the susceptibility to preeclampsia (PE) has not been elucidated yet. We, therefore, conducted a case-control study to evaluate the impact of polymorphisms in DGCR8 on the risk of EOPE and LOPE.

Methods

A total of 66 patients diagnosed with EOPE, 206 with LOPE and 330 healthy controls were recruited. Five SNPs in DGCR8 were genotyped including rs1558496, rs1640299, rs720012, rs720014, and rs9606241. Logistic regression was used to estimate the OR and the 95% CI for the associations.

Results

Increased risk of LOPE has been observed among patients with rs1640299 TG genotype (OR = 1.98 (95%CI: 1.38, 2.87), p = 2.32e-4) and rs720014 TC genotype (OR = 2.49 (95%CI: 1.72, 3.60), p = 1.40e-7). The DGCR8 rs1558496/ rs1640299/ rs720012/ rs720014/ rs9606241 haplotype T-G-A-C-A and T-G-A-C-G were associated with increased risk of LOPE (OR = 2.20 (95%CI: 1.49, 3.25), p = 5.90e-5, and 1.58 (95%CI: 1.06, 2.36), p = 0.024, respectively). And the haplotype T-T-G-T-A was associated with lower risk of LOPE (OR = 0.74 (95%CI: 0.58, 0.95), p = 0.018). These significant associations retained after false-positive discovery rate correction. However, none of the tested SNPs or haplotypes in DGCR8 gene is associated with risk of EOPE (p > 0.05).

Conclusions

Polymorphisms in DGCR8 might participate in the pathological process of preeclampsia. The rs1640299 T > G and rs720014 T > C polymorphisms are associated with late onset preeclampsia susceptibility.

Electronic supplementary material

The online version of this article (10.1186/s12881-019-0887-7) contains supplementary material, which is available to authorized users.

Investigation of GLUT1, HIF1α and TBX21 Gene Polymorphisms in Laryngeal Cancer

Objective

We aimed to investigate the association of the frequency of three single-nucleotide polymorphisms [glucose transporter isoform 1 (GLUT1) reference single-nucleotide polymorphism (rs) 710218, hypoxia-inducible factor 1 alpha (HIF1α) rs11549465, and T-box transcription factor protein 21 (TBX21) rs17250932], which have been proved to be related with various benign and malignant diseases, with the development of laryngeal cancer and its size and grade.

Methods

In this study, we included 35 patients with laryngeal cancer and 35 volunteers at least 30 years old who had smoked for at least 20 years. DNA was obtained from the blood samples of the participants using an isolation kit. Then, polymorphisms for both the groups were determined using real-time polymerase chain reaction.

Results

No significant differences were detected regarding the genotype and allele frequencies in the three polymorphisms assessed between the two groups. In the patient group, on examining the association of polymorphisms with tumor size and grade, no significant relation was observed in three polymorphisms regarding the related parameters.

Conclusion

GLUT1, HIF1α, and TBX21 polymorphisms have no impact on the development of laryngeal cancer.

The association of the placental Hypoxia-inducible factor1-α polymorphisms and HIF1-α mRNA expression with preeclampsia

INTRODUCTION

Evidence has confirmed that placental/fetal hypoxia plays a key role in both endothelial cell dysfunction and PE pathogenesis. The aim of the present study was to investigate whether maternal/placental hypoxia-inducible factor1-α (HIF1-α) C1772T (rs11549465) and/or G1790A (rs11549467) polymorphisms and HIF1-α mRNA expression are associated with PE development.

METHODS

The blood samples of 203 PE and 202 control women and the placenta of 86 PE and 84 control women were collected after delivery. The HIF1-α polymorphisms were genotyped using PCR- RFLP method. The mRNA expression levels were measured by Quantitative Real -Time PCR.

RESULTS

The present study found no association between maternal HIF1-α rs11549465 and rs11549467 and placental rs11549467 polymorphisms and PE. However, the placental rs11549465 polymorphism was associated with PE in the dominant model. The CT/GG combined genotypes and TG haplotype of placental rs11549465 and rs11549467 polymorphisms were associated with higher risk of PE. The HIF1-α mRNA expression was 3-fold higher in the PE women. The rs11549465 TT genotype was associated with higher HIF1-α mRNA expression in PE women and in total population and rs11549467 GA genotype was associated with higher mRNA expression in total population. The relative mRNA expression of HIF1-α gene was higher in presence of CC/GA, TT/GG and TT/GA combined genotypes.

CONCLUSION

This study found an association between placental but not maternal HIF1-α rs11549465 polymorphism and PE in the dominant model. The HIF1-α mRNA expression was higher in the placenta of PE women and was associated with rs11549465 and rs11549467 polymorphisms.

HIF1A gene rs10873142 polymorphism is associated with risk of chronic obstructive pulmonary disease in a Chinese Han population: a case-control study

Chronic obstructive pulmonary disease (COPD) is a type of obstructive lung disease characterized by long-term poor airflow. Recently, variants in the hypoxia inducible factor 1α (HIF1A) gene were found to be associated with COPD risk. The present study aimed to identify whether rs10873142 polymorphism (an intronic polymorphism) in HIF1A gene was related to COPD in a Chinese population. We genotyped HIF1A gene rs10873142 polymorphism in a case–control study with 235 COPD cases and 548 controls in a Chinese Han population. Odd ratios (ORs) and 95% confidence intervals (CIs) were estimated using the chi-squared (χ²) test, genetic model analysis, and stratification analysis. In the genetic model analysis, we found that the TT genotype (TT compared with CC: OR: 1.63; 95% CI: 1.02–2.60; P=0.042) and T allele (T compared with C: OR: 1.29; 95%CI, 1.02–1.60; P=0.032) showed significant correlation with the risk of COPD. However, in stratification analyses of age, BMI, and forced expiratory volume in 1 s (FEV1)/FEV, we failed to find any association between HIF1A gene rs10873142 polymorphism with COPD risk. The present study supports that HIF1A gene rs10873142 polymorphism may be associated with increased risk of COPD in a Chinese Han population. To the best of our knowledge, this is the first case–control study uncovering that the HIF1A gene rs10873142 polymorphism increases the risk of COPD in a Chinese Han population.

HIF1A gene polymorphisms and human diseases: Graphical review of 97 association studies

Hypoxia-inducible factors (HIFs) belong to a family of transcription factors (TF) responsive to a low O2 availability, which is often a characteristic feature of solid tumors. The alpha subunit of the HIF heterodimer is O2 -sensitive, and once stabilized in hypoxia, it functions as a master regulator of various genes involved in hypoxia pathway. Changes in the HIF1A (hypoxia inducible factor 1, alpha subunit) nucleotide sequence or expression has been shown to be associated with the development of several diseases. Because of increasing research interest in HIF1A gene a review of association studies was needed. We here reviewed published data on single nucleotide polymorphisms (SNPs) in HIF1A in various diseases; in total, 34 SNPs were tested for an association with 49 phenotypes, and the results were visualized using the Cytoscape software. Among all collected polymorphisms 16 SNPs showed significant associations with 40 different phenotypes, including six SNPs associated with 14 cancer types. Missense SNPs (rs11549465 and rs11549467) within the oxygen-dependent degradation domain were most frequently studied. The study provides a comprehensive tool for researchers working in this area and may contribute to more accurate disease diagnosis and identification of therapeutic targets.

The INSR rs2059806 single nucleotide polymorphism, a genetic risk factor for vascular and metabolic disease, associates with pre-eclampsia

Pre-eclampsia is a risk factor for later life vascular and metabolic diseases. This study postulates that this reflects a common genetic cause, and investigates whether the INSR rs2059806 single nucleotide polymorphism (SNP) (a risk factor for essential hypertension, type 2 diabetes and metabolic syndrome) is also associated with pre-eclampsia. The association of INSR rs2059806 with pre-eclampsia was tested in two cohorts - a Caucasian case control group (123 pre-eclamptic mother-father-baby trios and 1185 mother-father-baby trios from uncomplicated pregnancies) and an independent cohort of Sinhalese women (175 women with pre-eclampsia and 171 women with uncomplicated pregnancies). In the Caucasian cohort, the prevalence of the INSR rs2059806 AA genotype was greater among pre-eclamptic women compared with the uncomplicated pregnancies (12.7% versus 4.7%, OR[95%CI] = 3.1[1.6-5.8], P = 0.0003). In the Sinhalese cohort, maternal INSR rs2059806 AA genotype was greater among pre-eclamptic women who delivered small for gestational age infants compared with the uncomplicated pregnancies (10.8% versus 4.2%, OR[95%CI] = 2.8[1.0-7.4], P = 0.03). Thus, it was found that the INSR rs2059806 SNP is also associated with pre-eclampsia phenotypes in two independent cohorts suggesting that genetic susceptibility may be implicated in the link between pre-eclampsia and subsequent vascular and metabolic diseases.