Association Between TLR4 Gene Polymorphisms and Risk of Preeclampsia: Systematic Review and Meta-Analysis

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.

Gestationally administered RAS modulators reprogram endotoxic cardiovascular and inflammatory profiles in adult male offspring of preeclamptic rats

Previous studies showed that preeclampsia (PE) amplifies cardiovascular dysfunction induced by endotoxemia in adult male, but not female, offspring. Here, we asked if such aggravated endotoxic insult could be nullified by modulators of the renin-angiotensin system (RAS). PE was induced by gestational administration of Nω-nitro-L-arginine methyl ester(L-NAME, a nitric oxide synthase inhibitor). Adult male offspring of PE mothers treated gestationally with angiotensin 1-7 (Ang1-7, angiotensin II-derived vasodilator), losartan (AT1 receptor antagonist), pioglitazone (peroxisome proliferator-activated receptor gamma, PPARγ, agonist), or combined losartan/pioglitazone were instrumented with femoral indwelling catheters and challenged intravenously with a 5-mg/kg dose of lipopolysaccharides (LPS, 5 mg/kg). LPS caused significant decreases in blood pressure (BP) and spectral index of overall heart rate variability and increases in heart rate and left ventricular contractility (dP/dtmax). These effects were mostly reduced to similar magnitudes by individual drug therapies. In offspring born to Ang1-7-treated dams, the spectral index of cardiac sympathovagal balance showed elevated sympathetic dominance in response to LPS. Immunohistochemistry revealed that Ang1-7, but not losartan/pioglitazone, abolished the exaggerated increases in toll-like receptor 4 (TLR-4) expression caused by PE/LPS in heart tissues and neuronal circuits of brainstem rostral ventrolateral medulla (RVLM). By contrast, the losartan/pioglitazone regimen, but not Ang1-7, decreased and increased angiotensin converting enzyme (ACE) and ACE2 expression, respectively. Together, gestational fetal reprogramming of Ang II (depression) and Ang1-7 (activation) arms of RAS effectively counterbalance worsened endotoxic cardiovascular and inflammatory profiles in adult male offspring of PE rats.

The relationship between Toll-like receptor-4 genes and preeclampsia outcomes

PURPOSE

The study aimed to analyse the relationship of the rs4986790 locus of the TLR4 gene with the overall risk of preeclampsia, including both its early and late forms.

METHODS

The study used standard genetic analysis methods such as DNA extraction, PCR amplification, and genotyping of the rs4986790 locus of the TLR4 gene to assess the association with the development of preeclampsia and peripartal stroke in 207 pregnant women from the southern regions of Kazakhstan from 2016 to 2022, of whom 103 had peripartal stroke on the background of preeclampsia (the main group) and 104 preeclampsia (comparative group).

RESULTS

The results of the study demonstrate that the AG and AG + GG genotypes at the rs4986790 locus of the TLR4 gene are significantly associated with an increased risk of developing an early form of preeclampsia. This opens up a new perspective in the identification of genetic markers that can serve as indicators of a tendency to develop preeclampsia in earlier periods of pregnancy.

CONCLUSION

It was noted that the rs4986790 locus did not show a statistically significant association with the risk of late preeclampsia. An important aspect of the study revealed the relationship of genotypes with the development of peripartal stroke on the background of preeclampsia. This study offers practical insights for creating targeted genetic screening and personalised treatments for preeclampsia, aiming to improve patient outcomes. To fully understand the molecular mechanisms underlying the identified association, additional research is required to identify deeper molecular pathways and relationships, and to develop new strategies for the prevention and treatment of preeclampsia.

Impact of Survivin rs9904341 and rs17878467 Polymorphisms On Risk of Preeclampsia in Iran

Preeclampsia (PE) is a hypertensive disorder that affects pregnancy, mother, and fetus. Early diagnosis of PE remains a challenge. This study aimed to investigate the association between survivin two (rs9904341 and rs17878467) SNPs and PE risk in healthy pregnant women compared to women with preeclampsia. A sample of 166 healthy pregnant women and 160 cases with preeclampsia was included and genotyped for rs9904341 with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and rs17878467 with amplification-refractory mutation system (ARMS) PCR. The genotypic and allelic assessments were performed using various statistical approaches. The frequency of rs9904341 and rs17878467 polymorphisms was not significantly different between PE and healthy pregnant women. rs9904341: codominant (p = 0.5), dominant (p = 0.24), recessive (p = 0.61), over-dominant model (p = 0.38), and log additive (p = 0.25). rs17878467: codominant (p = 0.41), dominant (p = 0.23), recessive (p = 0.4), over-dominant model (p = 0.42), and log additive (p = 0.24). The frequency of survivin rs9904341 CG and CC genotypes was higher in severe PE women compared to controls and this polymorphism was associated with PE severity only in the dominant model (OR = 1.84, CI 1.04-3.26, P = 0.034). There was a significant association between survivin rs9904341 polymorphism and PE severity. No relationship was found between survivin rs9904341 and rs17878467 polymorphisms and PE onset. The allelic and genotypic frequencies of survivin rs9904341 and rs17878467 polymorphisms are not significantly different between the preeclampsia and control groups in all genetic models. Haplotype analysis showed lower frequency G rs9904341 T rs17878467 haplotype in PE woman and this haplotype was associated with lower risk of PE (OR = 0.54, CI 0.33-0.91, P = 0.02).

Genetic Association of Toll-Like Receptor 4 (TLR4) Gene Polymorphism (rs4986790) With Oral Squamous Cell Carcinoma (OSCC): A Pilot Case-Control Study

Introduction Oral squamous cell carcinoma (OSCC) is a highly prevalent and most common form of oral malignancy in the Indian population. Toll-like receptors belong to an important family of receptors that are involved in the process of pathogen recognition and mounting immune response. The expression of this receptor is dysregulated on the tumor cells as reported across several cancer types. The genetic variants in this gene could have a profound impact on the expression of the Toll-like receptor 4 (TLR4) gene.  Objective This study aimed to understand the association of TLR4 gene polymorphism (rs4986790) with OSCC. The objective of this study was to compare the allele and genotype frequencies between the two groups, viz., OSCC and normal healthy subjects, recruited in the study. Materials and methods The blood samples were collected from normal healthy subjects (N = 25) and OSCC patients (N = 25). Genomic DNA was isolated from all samples, and genotyping was performed for the TLR4 gene polymorphism (rs4986790) employing the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) approach. The frequency distribution of genotypes and alleles across the study groups was determined by the Chi-square test.  Results The allele frequency for TLR4 gene polymorphism (rs4986790) in the case group was found to be 60% (A allele) and 40% (G allele), respectively. The study population in both groups were found to agree with the Hardy-Weinberg equilibrium (HWE). The genotype frequency did not differ significantly among the two study groups which was evident from the p-value = 0.8285.  Conclusion The present study did not report any significant association of the TLR4 polymorphic marker rs4986790 with OSCC. Further investigations into the association of other polymorphic markers in the TLR4 gene, among the larger population of OSCC patients, could provide evidence of their association with OSCC.

Genetic variation in toll-like receptor 4 gene with primary antiphospholipid syndrome susceptibility: a cohort of Egyptian patients

Background

As toll-like receptor 4 (TLR4) plays important roles in cellular immunity and TLR4 polymorphisms have been shown to be associated with susceptibility to a range of diseases, the present study aimed to investigate the association between TLR4 gene polymorphisms and the incidence of primary antiphospholipid syndrome (PAPS).

Methods

Two TLR4 single nucleotide polymorphisms (rs4986790 and rs4986791) were assessed in 110 subjects of Egyptian ethnicity, including 65 female patients with PAPS and 45 matched healthy controls, using polymerase chain reaction-restriction fragment length polymorphism. Results were verified using automated sequencing.

Results

The homozygous wild-type (AA, aspartic acid) rs4986790 variant and (CC, threonine) rs4986791 variant were the predominant genotypes in the control and PAPS groups.

Conclusion

The results of this preliminary study of TLR4 gene variants among patients with PAPS in an Egyptian population found no association between the rs4986790 and rs4986791 variants and susceptibility to PAPS.