Genetic Polymorphism of Microsomal Epoxide Hydrolase Enzyme Gene in Preeclamptic Females

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.

A study of the association between angiotensinogen (AGT) gene polymorphism (M235T) and preeclampsia in Thai pregnant women

AGT M235T gene polymorphism may cause increased blood pressure in preeclampsia in pregnancy; however, the evidence remains controversial. This study investigated the association between AGT M235T and preeclampsia in Thai pregnant women. A case-control study was conducted to compare the distributions of AGT M235T genotypes and alleles between 142 normotensive pregnancies as controls and 61 preeclampsia pregnancies as cases in a tertiary-care university hospital in Chiang Mai, Thailand. The results show that the distribution of AGT M235T genotypes (MM, MT and TT) of both groups were not significantly different (preeclampsia: 0.0, 16.4, 83.6%; control: 2.1, 22.5, 75.4%, respectively; p = .30). Additionally, there was no statistical difference in the distribution of AGT M235T alleles (M and T alleles) (preeclampsia: 8.2 and 91.8% versus control: 13.4 and 86.6%, respectively; p = .14). In this study, the distributions of AGT M235T were not different in both groups. Therefore, AGT M235T polymorphism may not play a significant role in preeclampsia pathophysiology in Thai population.Impact statementWhat is already known on this subject? Preeclampsia is one of the major complications during pregnancy; it significantly affects maternal and perinatal morbidity and mortality. Effort has been made to find markers and predictors that are associated with the pathophysiology of preeclampsia. AGT M235T gene polymorphism may cause increased blood pressure in preeclampsia pregnancy; however, evidences are still controversial.What do the results of this study add? We conducted a case-control study to compare the distributions of AGT M235T genotypes and alleles between 142 normotensive pregnancies as controls and 61 preeclampsia pregnancies as cases. The results show that preeclamptic women are more likely to deliver at an earlier gestational age and have a smaller baby in comparison with the normotensive group. In addition, women with preeclampsia had a higher chance of having an operative delivery and caesarean section. However, the distribution of AGT M235T polymorphism of preeclampsia women and the control group were not significantly different.What are the implications of these findings for clinical practice and/or further research? AGT M235T polymorphism may not play a significant role in preeclampsia pathophysiology in Thai population.

CXC Chemokine Receptor Type 5 Gene Polymorphisms in a Cohort of Egyptian Patients with Diffuse Large B-Cell Lymphoma

BACKGROUND

The chemokine receptor CXCR5 is selectively expressed on B cells; it is involved in lymphocyte homing and the development of normal lymphoid tissue. Its principle ligand is CXCL13 or B lymphocyte chemoattractant. Three polymorphisms in the CXCR5 gene, rs148351692 C/G, rs6421571 C/T, and rs78440425 G/A, have been identified.

OBJECTIVE

To assess the genetic polymorphisms of CXCR5 and evaluate their possible contribution to the susceptibility and response to therapy of diffuse large B-cell lymphoma (DLBCL).

PATIENTS AND METHODS

Fifty DLBCL (not otherwise specified) patients and 50 control subjects were included in this study. CXCR5 genotypes were determined by PCR-RFLP.

RESULTS

Our study revealed that the CXCR5 rs148351692 C/G and rs6421571 C/T gene polymorphisms are associated with an increased risk of developing DLBCL (OR 28.57 [95% CI 8.96-96.56] and 3.45 [1.67-11.83] respectively), while CXCR5 rs78440425 G/A showed no association with the risk of lymphoma. Moreover, the double and triple combined gene polymorphisms are associated with an increased risk of developing DLBCL of approximately 120-fold and 105-fold, respectively. CXCR5 gene polymorphisms had no significant impact on disease outcome or response to therapy.

CONCLUSIONS

CXCR5 gene polymorphisms could be considered a potential risk factor for the development of DLBCL.

Association of Four Missense SNPs with Preeclampsia in Saudi Women

Objective:

The objective of this study was to investigate the association of rs1051740, rs2234922 (in microsomal epoxide hydrolase 1; EPHX1), rs268 (in lipoprotein lipase; LPL) and rs6025 (in Factor V Leiden; F5) genetic variants with the risk of preeclampsia development in Saudi women.

Materials and Methods:

This case–control study recruited 233 Saudi women (94 preeclampsia cases and 139 healthy controls) who visited the Gynecology and Obstetrics Departments of two hospitals in Jeddah, Saudi Arabia, for routine postpregnancy clinical follow-ups. All the women underwent thorough clinical and biochemical investigations conducted according to the standard clinical guidelines. Genotyping of the study participants was done using real-time polymerase chain reaction-based TaqMan allelic discrimination assay. The strength of the association between genetic variants and disease development was assessed using chi-square, odds ratio, 95% confidence interval and multifactor dimensionality reduction tests.

Result:

The minor alleles “G” in rs268 (LPL) and “A” in rs6025 (F5) were absent in Saudi women. The frequencies of rs1051740 and rs2234922 of EPHX1, both in the homozygous and allelic forms, were not significantly different between preeclampsia patients and healthy controls (for all tests, P > 0.05). The multifactor dimensionality reduction analysis also indicated that the interaction between the four studied single-nucleotide polymorphisms (SNPs) had no significant association with preeclampsia risk.

Conclusion:

This study found that none of the studied genetic variants (neither the single SNP nor the SNP–SNP interactions) explain the development of preeclampsia in the Saudi population. These findings not only underscore the disease heterogeneity but also highlight the need to develop population-specific diagnostic genetic biomarkers for preeclampsia.

The clinical relevance and prognostic significance of microsomal epoxide hydrolase gene polymorphisms and their susceptibility to acquired aplastic anemia: an Egyptian study

BACKGROUND

Microsomal epoxide hydrolase enzyme (mEPHX) is involved in xenobiotics detoxification. Two variants of mEPHX, Tyr113His and His139Arg, have been described. Both may lead to acquired aplastic anemia (AA).

OBJECTIVES

Assessing mEPHX genetic polymorphisms and detecting their impact on susceptibility and prognosis in Egyptian AA patients.

PARTICIPANTS AND METHODS

mEPHX 113 and 139 genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in 100 patients with AA and 100 control subjects.

RESULTS

Both mEPHX Tyr113His and His139Arg gene polymorphisms were associated with increased risk of developing AA, and have a significant impact of bad prognosis (p value < 0.01).

CONCLUSIONS

These mEPHX gene polymorphisms can be considered as risk factors and predictive molecular markers for prognosis in AA patients.

The role of epoxide hydrolases in health and disease

Epoxide hydrolases (EH) are ubiquitously expressed in all living organisms and in almost all organs and tissues. They are mainly subdivided into microsomal and soluble EH and catalyze the hydration of epoxides, three-membered-cyclic ethers, to their corresponding dihydrodiols. Owning to the high chemical reactivity of xenobiotic epoxides, microsomal EH is considered protective enzyme against mutagenic and carcinogenic initiation. Nevertheless, several endogenously produced epoxides of fatty acids function as important regulatory mediators. By mediating the formation of cytotoxic dihydrodiol fatty acids on the expense of cytoprotective epoxides of fatty acids, soluble EH is considered to have cytotoxic activity. Indeed, the attenuation of microsomal EH, achieved by chemical inhibitors or preexists due to specific genetic polymorphisms, is linked to the aggravation of the toxicity of xenobiotics, as well as the risk of cancer and inflammatory diseases, whereas soluble EH inhibition has been emerged as a promising intervention against several diseases, most importantly cardiovascular, lung and metabolic diseases. However, there is reportedly a significant overlap in substrate selectivity between microsomal and soluble EH. In addition, microsomal and soluble EH were found to have the same catalytic triad and identical molecular mechanism. Consequently, the physiological functions of microsomal and soluble EH are also overlapped. Thus, studying the biological effects of microsomal or soluble EH alterations needs to include the effects on both the metabolism of reactive metabolites, as well as epoxides of fatty acids. This review focuses on the multifaceted role of EH in the metabolism of xenobiotic and endogenous epoxides and the impact of EH modulations.