An intron variant in the FLT1 gene increases the risk of preeclampsia in Iranian women

Association of angiogenic factors (placental growth factor and soluble FMS-like tyrosine kinase-1) in preeclamptic women of African ancestry comorbid with HIV infection

BACKGROUND

Preeclampsia is a significant cause of maternal and fetal morbidity and mortality, particularly in low- and middle-income countries like South Africa.

AIM

The aim of our study was to investigate the association between placental growth factor (PlGF) and soluble FMS-like tyrosine kinase-1 (sFlt-1) in South African preeclamptic women of African ancestry, comorbid with HIV infection.

METHODS

The study population consisted of women attending a regional hospital in Durban, South Africa, stratified by pregnancy type (normotensive pregnant and preeclampsia) and HIV status. Preeclampsia was defined as new-onset hypertension and proteinuria. DNA was obtained from whole blood. The SNPs of interest were rs722503 in sFlt-1 and rs4903273 in PlGF.

RESULTS

Our findings suggest that single nucleotide polymorphisms of rs722503 analysis show no significant associations between the genotypic frequencies of rs722503 variants and preeclampsia risk in either HIV-negative or HIV-positive groups of women of African ancestry. Similarly, the rs493273 polymorphism showed no significant association with preeclampsia risk in either HIV-negative or HIV-positive pregnant women. Additionally, comparisons of dominant, recessive, and over-dominant allele models did not reveal significant associations. These findings suggest that these genetic variants may not significantly contribute to preeclampsia development in this African ancestry population. However, significant differences were observed in the rs4903273 genotype frequencies between normotensive and preeclamptic women, regardless of HIV status, over dominant alleles AA + GG vs AG showed a significant difference [OR = 2.706; 95% Cl (1.199-5.979); adjusted p = 0.0234*], also in normotensive compared to EOPE (OR = 2.804; 95% Cl (1.151-6.89) p = 0.0326* and LOPE (OR = 2.601; 95% Cl (1.0310-6.539) p = 0.0492*), suggesting that they may be the potential role of this variant in preeclampsia susceptibility.

CONCLUSION

The findings suggest that the rs722503 and rs493273 polymorphisms do not significantly contribute to preeclampsia susceptibility in HIV-negative or HIV-positive pregnant women. However, the rs4903273 genotype frequencies showed notable differences between normotensive and preeclamptic women, indicating a potential association with preeclampsia development in the African ancestry population irrespective of HIV status.

Association between rs1799724 of TNF- α gene and early onset preeclampsia in Chinese: A pilot study

Objective

To investigate the association between polymorphisms of TNF- α (rs1799724, rs1800629), VEGF (rs3025039) and VEGFR1 (rs 722503) and early onset preeclampsia (EOPE) in Chinese.

Methods

A total of 132 EOPE patients from January 2016 to December 2018 at the Second Hospital of Tianjin Medical University were selected as the EOPE group, and 156 normal pregnant patients as the Control group. In both groups, 5 ml of peripheral venous blood was obtained after admission. The characteristics of genotype and allele distribution at the four SNPs in the study subjects were examined by matrix-assisted laser desorption ionization time-of-flight mass spectrometric genotyping.

Results

The genotype frequency distribution and allele frequency distribution of rs1799724 were significantly different between the EOPE group and the Control group (P = 0.002，P = 0.003). The T allele was statistically associated with the development of EOPE under a dominant genetic model (P = 0.001). The genotype and allele frequency distributions of rs1800629, rs3025039, and rs 722503 did not differ significantly between the EOPE group and the Control group (P > 0.05). There was no linkage disequilibrium among rs1799724, rs1800629 and rs3025039 loci, the corresponding haploid cannot be formed.

Conclusions

The rs1799724 of TNF- α gene is a genetic susceptibility locus for EOPE and may be a potential predictors of preeclampsia.

Polymorphic Variants of Genes Encoding Angiogenesis-Related Factors in Infertile Women with Recurrent Implantation Failure

Recurrent implantation failure (RIF) is a global health issue affecting a significant number of infertile women who undergo in vitro fertilization (IVF) cycles. Extensive vasculogenesis and angiogenesis occur in both maternal and fetal placental tissues, and vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF) family molecules and their receptors are potent angiogenic mediators in the placenta. Five single nucleotide polymorphisms (SNPs) in the genes encoding angiogenesis-related factors were selected and genotyped in 247 women who had undergone the ART procedure and 120 healthy controls. Genotyping was conducted by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). A variant of the kinase insertion domain receptor (KDR) gene (rs2071559) was associated with an increased risk of infertility after adjusting for age and BMI (OR = 0.64; 95% CI: 0.45-0.91, p = 0.013 in a log-additive model). Vascular endothelial growth factor A (VEGFA) rs699947 was associated with an increased risk of recurrent implantation failures under a dominant (OR = 2.34; 95% CI: 1.11-4.94, p_adj. = 0.022) and a log-additive model (OR = 0.65; 95% CI 0.43-0.99, p_adj. = 0.038). Variants of the KDR gene (rs1870377, rs2071559) in the whole group were in linkage equilibrium (D' = 0.25, r² = 0.025). Gene-gene interaction analysis showed the strongest interactions between the KDR gene SNPs rs2071559-rs1870377 (p = 0.004) and KDR rs1870377-VEGFA rs699947 (p = 0.030). Our study revealed that the KDR gene rs2071559 variant may be associated with infertility and rs699947 VEGFA with an increased risk of recurrent implantation failures in infertile ART treated Polish women.

Pre-Existing Diabetes Mellitus, Hypertension and KidneyDisease as Risk Factors of Pre-Eclampsia: A Disease of Theories and Its Association with Genetic Polymorphism

Pre-existing diabetes, hypertension and kidney disorders are prominent risk factors of pre-eclampsia (PE). It is a multifactorial pregnancy disorder associated with high blood pressure, proteinuria, and multiorgan failure, which develops after the 20th week of pregnancy. It is one of the most feared pregnancy disorders, as it consumes thousands of fetomaternal lives per annum. According to clinical and pathological studies, the placenta appears to be a key player in the pathogenesis of PE; however, the exact origin of this disorder is still under debate. Defective placentation and angiogenesis are the hallmarks of PE progression. This angiogenic imbalance, together with maternal susceptibility, might determine the severity and clinical presentation of PE. This article comprehensively examines the mechanisms of pathogenesis of PE and current evidence of the factors involved in its progression. Finally, this article will explore the genetic association of PE, various candidate genes, their proposed mechanisms and variants involved in its pathogenesis.

Association of Single Nucleotide Polymorphisms from Angiogenesis-Related Genes, ANGPT2, TLR2 and TLR9, with Spontaneous Preterm Labor

In this study, we hypothesized that the changes localized at angiopoietin-2 (ANGPT2), granulocyte-macrophage colony-stimulating factor (CSF2), fms-related tyrosine kinase 1 (FLT1) and toll-like receptor (TLR) 2, TLR6 and TLR9 genes were associated with spontaneous preterm labor (PTL), as well as with possible genetic alterations on PTL-related coagulation. This case-control genetic association study aimed to identify single nucleotide polymorphisms (SNPs) for the aforementioned genes, which are correlated with genetic risk or protection against PTL in Polish women. The study was conducted in 320 patients treated between 2016 and 2020, including 160 women with PTL and 160 term controls in labor. We found that ANGPT2 rs3020221 AA homozygotes were significantly less common in PTL cases than in controls, especially after adjusting for activated partial thromboplastin time (APTT) and platelet (PLT) parameters. TC heterozygotes for TLR2 rs3804099 were associated with PTL after correcting for anemia, vaginal bleeding, and history of threatened miscarriage or PTL. TC and CC genotypes in TLR9 rs187084 were significantly less common in women with PTL, compared to the controls, after adjusting for bleeding and gestational diabetes. For the first time, it was shown that three polymorphisms-ANGPT2 rs3020221, TLR2 rs3804099 and TLR9 rs187084 -were significantly associated with PTL, adjusted by pregnancy development influencing factors.

Prediction of Differentially Expressed Genes and a Diagnostic Signature of Preeclampsia via Integrated Bioinformatics Analysis

Background

Preeclampsia (PE), which has a high incidence rate worldwide, is a potentially dangerous syndrome to pregnant women and newborns. However, the exact mechanism of its pathogenesis is still unclear. In this study, we used bioinformatics analysis to identify hub genes, establish a logistic model, and study immune cell infiltration to clarify the physiopathogenesis of PE.

Methods

We downloaded the GSE75010 and GSE10588 datasets from the GEO database and performed weighted gene coexpression network analysis (WGCNA) as well as Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. The online search tool for the retrieval of interacting genes and Cytoscape software were used to identify hub genes, which were then used to establish a logistic model. We also analyzed immune cell infiltration. Finally, we verified the expression of the genes included in the predictive model via RT-PCR.

Results

A total of 100 and 212 differently expressed genes were identified in the GSE75010 and GSE10588 datasets, respectively, and after overlapping with WGCNA results, 17 genes were identified. KEGG and GO analyses further indicated the involvement of these genes in bioprocesses, such as gonadotropin secretion, immune cell infiltration, and the SMAD and MAPK pathways. Additionally, protein-protein interaction network analysis identified 10 hub genes, six (FLT1, FLNB, FSTL3, INHA, TREM1, and SLCO4A1) of which were used to establish a logistic model for PE. RT-PCR analysis also confirmed that, except FSTL3, these genes were upregulated in PE. Our results also indicated that macrophages played the most important role in immune cell infiltration in PE.

Conclusion

This study identified 10 hub genes in PE and used 6 of them to establish a logistic model and also analyzed immune cell infiltration. These findings may enhance the understanding of PE and enable the identification of potential therapeutic targets for PE.

Single Nucleotide Polymorphisms from CSF2, FLT1, TFPI and TLR9 Genes Are Associated with Prelabor Rupture of Membranes

A prelabor rupture of membranes (PROM) and its subtypes, preterm PROM (pPROM) and term PROM (tPROM), are associated with disturbances in the hemostatic system and angiogenesis. This study was designed to demonstrate the role of single nucleotide polymorphisms (SNPs), localized in CSF2 (rs25881), FLT1 (rs722503), TFPI (C-399T) and TLR9 (rs352140) genes, in PROM. A population of 360 women with singleton pregnancy consisted of 180 PROM cases and 180 healthy controls. A single-SNP analysis showed a similar distribution of genotypes in the studied polymorphisms between the PROM or the pPROM women and the healthy controls. Double-SNP TT variants for CSF2 and FLT1 polymorphisms, CC variants for TLR9 and TFPI SNPs, TTC for CSF2, FLT1 and TLR9 polymorphisms, TTT for FLT1, TLR9 and TFPI SNPs and CCCC and TTTC complex variants for all tested SNPs correlated with an increased risk of PROM after adjusting for APTT, PLT parameters and/or pregnancy disorders. The TCT variants for the CSF2, FLT1 and TLR9 SNPs and the CCTC for the CSF2, FLT1, TLR9 and TFPI polymorphisms correlated with a reduced risk of PROM when corrected by PLT and APTT, respectively. We concluded that the polymorphisms of genes, involved in hemostasis and angiogenesis, contributed to PROM.

Hypoxia-induced small extracellular vesicle proteins regulate proinflammatory cytokines and systemic blood pressure in pregnant rats

Small extracellular vesicles (sEVs) released from the extravillous trophoblast (EVT) are known to regulate uterine spiral artery remodeling during early pregnancy. The bioactivity and release of these sEVs differ under differing oxygen tensions and in aberrant pregnancy conditions. Whether the placental cell-derived sEVs released from the hypoxic placenta contribute to the pathophysiology of preeclampsia is not known. We hypothesize that, in response to low oxygen tension, the EVT packages a specific set of proteins in sEVs and that these released sEVs interact with endothelial cells to induce inflammation and increase maternal systemic blood pressure. Using a quantitative MS/MS approach, we identified 507 differentially abundant proteins within sEVs isolated from HTR-8/SVneo cells (a commonly used EVT model) cultured at 1% (hypoxia) compared with 8% (normoxia) oxygen. Among these differentially abundant proteins, 206 were up-regulated and 301 were down-regulated (P < 0.05), and they were mainly implicated in inflammation-related pathways. In vitro incubation of hypoxic sEVs with endothelial cells, significantly increased (P < 0.05) the release of GM-CSF, IL-6, IL-8, and VEGF, when compared with control (i.e. cells without sEVs) and normoxic sEVs. In vivo injection of hypoxic sEVs into pregnant rats significantly increased (P < 0.05) mean arterial pressure with increases in systolic and diastolic blood pressures. We propose that oxygen tension regulates the release and bioactivity of sEVs from EVT and that these sEVs regulate inflammation and maternal systemic blood pressure. This novel oxygen-responsive, sEVs signaling pathway, therefore, may contribute to the physiopathology of preeclampsia.

Association between Vascular Endothelial Growth Factor Gene Polymorphisms and Pre-Eclampsia Susceptibility: An Updated Meta-Analysis

Objectives: The aim of this study was to assess the genetic association between vascular endothelial growth factor (VEGF) gene polymorphisms and the risk of pre-eclampsia (PE).Methods: A systematic literature search of several databases (PubMed, Embase, and the China National Knowledge Infrastructure (CNKI)) was conducted for case-control trials comparing VEGF polymorphisms (+936C/T, -634G/C, -2578C/A, and -1154G/A) with the risk of PE. Meta-analysis was performed using the Stata 12.0 software.Results: Twenty-three case-control studies on a total of 2597 PE patients and 3075 controls were included in our meta-analysis. The +936C/T polymorphism was observed to be associated with the risk of PE in the overall population (T vs. C: odds ratios (OR) = 1.434, 95% confidence interval (CI) = 1.120-1.836, P = .004). However, the -634G/C, -2578C/A, and -1154G/A polymorphisms showed no association with the risk of PE. A subgroup analysis based on ethnicity found that the +936C/T polymorphism was associated with the risk of PE in both Europeans and Asians. Furthermore, the -634G/C polymorphism was found to be associated with the risk of PE in Europeans (C vs. G: OR = 1.428, 95% CI = 1.141-1.778, P = .002). The polymorphisms at other loci were not associated with the risk of PE.Conclusion: This meta-analysis suggests that VEGF +936C/T polymorphism, rather than -634G/C, -2578C/A, or -1154G/A polymorphisms, is associated with the risk of PE in the overall study population. However, the -634G/C polymorphism may be associated with the risk of developing PE in Europeans.