Effects of genetic polymorphisms of CYP2J2, CYP2C9, CYP2C19, CYP4F2, CYP4F3 and CYP4A11 enzymes in preeclampsia and gestational hypertension

INTRODUCTION

The aim of this study was to investigate the effects of cytochrome P450 (CYP) 2J2, CYP2C9, CYP2C19 and CYP4F2, CYP4F3 and CYP4A11 genetic polymorphisms in preeclampsia and gestational hypertension (GHT) patients in a sample of Turkish population.

MATERIALS-METHODS

Patients (n = 168; 110 GHT and 58 preeclampsia) and healthy pregnant women (n = 155, controls) participated in the study. For genotyping, polymerase chain reaction (PCR) and restriction analysis (RFLP) were used. Substance levels were measured using LC-MS.

RESULTS

Plasma DHET levels in GHT and preeclampsia patients were significantly lower than those in the control group (62.7%, 66.3% vs.100.0%, respectively, p < 0.0001). An increase in CYP2J2*7 allele frequency was observed in the preeclampsia group, as compared to GHT group (12.1% vs. 4.5%; odds ratio, O.R. = 2.88, p < 0.01). The frequencies of CYP2C19*2 and*17 alleles were higher in GHT group as compared to the control group (17.7% vs. 11.6%, O.R. = 1.99, p < 0.01; and 28.6% vs.18.4%, O.R. = 2.03, p < 0.01, respectively). An increased frequency of CYP4F3 rs3794987 G allele was found in GHT group as compared to the control group (48.0% vs. 38.0%; O.R. = 1.53, p < 0.01).

DISCUSSION

DHET plasma levels were significantly reduced in hypertensive pregnant groups as compared to the control group. The allele frequency distributions for CYP2J2*7, CYP2C19 *2, *17 and CYP4F3 rs3794987 were significantly different in hypertensive pregnant patients as compared to the healthy control subjects. Our results may suggest that investigated genetic polymorphisms may be useful in diagnosis and clinical management of GHT and preeclampsia patients.

Utility of China-PAR stroke equations for predicting 10-year stroke risk in the rural Inner Mongolian population in China

BACKGROUND

The aim of this study is to investigate the capability using the China-PAR stroke equations for predicting 10-year risk of stroke among the Inner Mongolian population in China.

METHODS

A prospective cohort study was conducted among 2535 rural Inner Mongolian residents from June 2002 to July 2012. Participants were categorized into four subgroups according to their 10-year predicted stroke risks calculated using the China-PAR stroke equations: <5%, 5-9.9%, 10-19.9%, and ≥20%.

RESULTS

The C-statistic of the China-PAR stroke equations for 10-year stroke was 0.58, and the result from Hosmer-Lemeshow 'goodness-of-fit' test showed that the China-PAR stroke equations fitted the Inner Mongolian women well (χ² = 11.18, P = 0.192). The adjusted hazard ratios of stroke were 3.86 (95% CI: 1.12-13.29) for 5-9.9% category, 10.37 (95% CI: 2.70-39.84) for 10-19.9% category, and 17.00 (95% CI: 3.54-81.63) for ≥20% category among Inner Mongolian women using the <5% category as reference (P for trend <0.001). However, the China-PAR stroke equations underestimated the 10-year stroke risk in Inner Mongolian men, and the calibration was unsatisfactory (χ² = 15.82, P = 0.045).

CONCLUSION

The China-PAR stroke equations have potential predictive ability for 10-year stroke risk in the rural Inner Mongolian women, while it might not suit the rural Inner Mongolian men well. The performance of China-PAR stroke equations in other ethnic groups in China will need to be further evaluated.

Sex differences in eicosanoid formation and metabolism: A possible mediator of sex discrepancies in cardiovascular diseases

Arachidonic acid is metabolized by cyclooxygenase, lipoxygenase, and cytochrome P450 enzymes to produce prostaglandins, leukotrienes, epoxyeicosatrienoic acids (EETs), and hydroxyeicosatetraenoic acids (HETEs), along with other eicosanoids. Eicosanoids have important physiological and pathological roles in the body, including the cardiovascular system. Evidence from several experimental and clinical studies indicates differences in eicosanoid levels, as well as in the activity or expression levels of their synthesizing and metabolizing enzymes between males and females. In addition, there is a clear state of gender specificity in cardiovascular diseases (CVD), which tend to be more common in men compared to women, and their risk increases significantly in postmenopausal women compared to younger women. This could be largely attributed to sex hormones, as androgens exert detrimental effects on the heart and blood vessels, whereas estrogen exhibits cardioprotective effects. Many of androgen and estrogen effects on the cardiovascular system are mediated by eicosanoids. For example, androgens increase the levels of cardiotoxic eicosanoids like 20-HETE, while estrogens increase the levels of cardioprotective EETs. Thus, sex differences in eicosanoid levels in the cardiovascular system could be an important underlying mechanism for the different effects of sex hormones and the differences in CVD between males and females. Understanding the role of eicosanoids in these differences can help improve the management of CVD.

Molecular Functionality of Cytochrome P450 4 (CYP4) Genetic Polymorphisms and Their Clinical Implications

Enzymes in the cytochrome P450 4 (CYP4) family are involved in the metabolism of fatty acids, xenobiotics, therapeutic drugs, and signaling molecules, including eicosanoids, leukotrienes, and prostanoids. As CYP4 enzymes play a role in the maintenance of fatty acids and fatty-acid-derived bioactive molecules within a normal range, they have been implicated in various biological functions, including inflammation, skin barrier, eye function, cardiovascular health, and cancer. Numerous studies have indicated that genetic variants of CYP4 genes cause inter-individual variations in metabolism and disease susceptibility. Genetic variants of CYP4A11, 4F2 genes are associated with cardiovascular diseases. Mutations of CYP4B1, CYP4Z1, and other CYP4 genes that generate 20-HETE are a potential risk for cancer. CYP4V2 gene variants are associated with ocular disease, while those of CYP4F22 are linked to skin disease and CYP4F3B is associated with the inflammatory response. The present study comprehensively collected research to provide an updated view of the molecular functionality of CYP4 genes and their associations with human diseases. Functional analysis of CYP4 genes with clinical implications is necessary to understand inter-individual variations in disease susceptibility and for the development of alternative treatment strategies.

Genetic role of CYP4A11 polymorphisms in the risk of developing cardiovascular and cerebrovascular diseases

BACKGROUND

We are interested in comprehensively evaluating the potential genetic influence of rs9332978 A/G, rs1126742 T/C, and rs9333025 G/A polymorphisms of CYP4A11 (cytochrome P450 family 4, subfamily A, member 11) in the risk of developing cardiovascular and cerebrovascular diseases.

METHODS

A meta-analysis was carried out using articles obtained from online databases and Stata/SE 12.0 software. We primarily used a P value of association test (P_association ) and odds ratios (OR) to assess the genetic relationships.

RESULTS

We included 22 eligible case-control articles for our meta-analysis. For the overall meta-analysis of the rs9332978 A/G polymorphism, there was an increased risk of cardiovascular and cerebrovascular diseases in cases under the models of allele G vs. A (P_association  = 0.001, OR = 1.16), AG vs. AA (P_association  < 0.001, OR = 1.22), and AG+GG vs. AA (P_association  < 0.001, OR = 1.22) compared with the controls. There were similar results in the subgroup analysis of "hypertension" (P_association  = 0.024 for the allele model; P_association  = 0.003 for the heterozygote model; and P_association  = 0.005 for the dominant model). For rs1126742, there was a significant difference between cases and controls in the overall meta-analysis and subgroup of "Caucasian," "hypertension," and "population-based (PB)" under all of the genetic models (all P_association  < 0.05, OR > 1). Furthermore, a decreased risk was detected in the overall and "PB" subgroup meta-analysis of rs9333025 under the models of A vs. G, AA vs. GG, and AA vs. GG+GA (all P_association  < 0.05, OR < 1).

CONCLUSION

The rs1126742 T/C polymorphism of CYP4A11 is more likely to be a genetic risk factor for the hypertension cases in the Caucasian population. Moreover, whereas the AG genotype of CYP4A11 rs9332978 may be associated with an increased risk of hypertension, the AA genotype of rs9333025 may be linked to a decreased risk of cardiovascular and cerebrovascular diseases.

20-HETE in the regulation of vascular and cardiac function

20-HETE, the ω-hydroxylation product of arachidonic acid catalyzed by enzymes of the cytochrome P450 (CYP) 4A and 4F gene families, is a bioactive lipid mediator with potent effects on the vasculature including stimulation of smooth muscle cell contractility, migration and proliferation as well as activation of endothelial cell dysfunction and inflammation. Clinical studies have shown elevated levels of plasma and urinary 20-HETE in human diseases and conditions such as hypertension, obesity and metabolic syndrome, myocardial infarction, stroke, and chronic kidney diseases. Studies of polymorphic associations also suggest an important role for 20-HETE in hypertension, stroke and myocardial infarction. Animal models of increased 20-HETE production are hypertensive and are more susceptible to cardiovascular injury. The current review summarizes recent findings that focus on the role of 20-HETE in the regulation of vascular and cardiac function and its contribution to the pathology of vascular and cardiac diseases.

Identification of potential candidate genes for hypertensive nephropathy based on gene expression profile

Background

This study was aimed to explore the molecular mechanisms of hypertensive nephropathy (HTN).

Methods

Gene expression profile of GSE37460, which based on 27 healthy living donor samples (HTN group) and 15 hypertensive nephropathy samples (control group), were downloaded from Gene Expression Omnibus (GEO) database. The differentially expressed genes (DEGs) between two groups were identified. STRING database was used to reveal protein-protein interaction (PPI) network of DEGs, followed by the functional enrichment analysis of the PPI network. Additionally, miRNA-DEG regulatory network was constructed to reveal the validated miRNAs targeting the DEGs.

Results

In total, 51 up-regulated genes and 140 down-regulated genes were obtained. In the PPI network, cytochrome P450 3A4 (CYP3A4) and angiotensin II receptor type 1 (AGTR1) had a higher degree, and CYP3A4 interacted with CYP4A11. The DEGs in the network were significantly enriched in drug metabolism, focal adhesion and arachidonic acid metabolism. Furthermore, in the miRNA-DEG regulatory network, hsa-miR-335-5p and hsa-miR-26b-5p were the two most outstanding miRNAs. AGTR1, CYP3A4 and CYP4A11 were predicted to be regulated by hsa-miR-26b-5p.

Conclusion

The DEGs, such as AGTR1, CYP3A4 and CYP4A11 may play critical roles in the development of HTN likely via the regulation by hsa-miR-26b-5p and taking part in some pathways.

Molecular mechanisms and cell signaling of 20-hydroxyeicosatetraenoic acid in vascular pathophysiology

Cytochrome P450s enzymes catalyze the metabolism of arachidonic acid to epoxyeicosatrienoic acids (EETs), dihydroxyeicosatetraenoic acid and hydroxyeicosatetraeonic acid (HETEs). 20-HETE is a vasoconstrictor that depolarizes vascular smooth muscle cells by blocking K+ channels. EETs serve as endothelial derived hyperpolarizing factors. Inhibition of the formation of 20-HETE impairs the myogenic response and autoregulation of renal and cerebral blood flow. Changes in the formation of EETs and 20-HETE have been reported in hypertension and drugs that target these pathways alter blood pressure in animal models. Sequence variants in CYP4A11 and CYP4F2 that produce 20-HETE, UDP-glucuronosyl transferase involved in the biotransformation of 20-HETE and soluble epoxide hydrolase that inactivates EETs are associated with hypertension in human studies. 20-HETE contributes to the regulation of vascular hypertrophy, restenosis, angiogenesis and inflammation. It also promotes endothelial dysfunction and contributes to cerebral vasospasm and ischemia-reperfusion injury in the brain, kidney and heart. This review will focus on the role of 20-HETE in vascular dysfunction, inflammation, ischemic and hemorrhagic stroke and cardiac and renal ischemia reperfusion injury.

Interaction Between CYP4F2 rs2108622 and CPY4A11 rs9333025 Variants Is Significantly Correlated with Susceptibility to Ischemic Stroke and 20-Hydroxyeicosatetraenoic Acid Level

AIMS

To investigate the association of four variants of two CYP ω-hydroxylase genes and 20-hydroxyeicosatetraenoic acid (HETE) levels with ischemic stroke (IS) and whether gene-gene interactions between these genes increase the risk of IS.

METHODS

Three hundred ninety-six patients with IS and 378 controls were genotyped for rs2269231, rs9333025, rs2108622, and rs3093135. Gene-gene interactions were analyzed using generalized multifactor dimensionality reduction (GMDR) methods. The 20-HETE levels was measured in 218 IS patients and 126 controls.

RESULTS

The frequency of the GG genotype of rs9333025 was significantly higher in IS patients than in controls (p < 0.001). The GMDR analysis showed a significant gene-gene interaction between rs9333025 and rs2108622 (p = 0.0116). This gene-gene interaction predicted a significantly higher risk of IS in individuals carrying the genotypes of rs9333025 GG and rs2108622 GG (odds ratio = 1.92, 95% confidence interval = 1.12-4.26, p = 0.007). The plasma levels of 20-HETE were significantly higher in IS patients than in controls, and IS patients carrying the genotype combination of rs9333025 GG and rs2108622 GG had higher 20-HETE levels than IS patients with other combinations of the two variants.

CONCLUSION

CYP4A1l rs9333025 GG and CYP4F2 rs2108622 GG two-loci interaction significantly increases the risk for IS and an elevated 20-HETE level.

Arachidonic acid monooxygenase: Genetic and biochemical approaches to physiological/pathophysiological relevance

Studies with rat genetic models of hypertension pointed to roles for the CYP2C and CYP4A arachidonic acid epoxygenases and ω-hydroxylases in tubular transport, hemodynamics, and blood pressure control. Further progress in defining their physiological functions and significance to human hypertension requires conclusive identifications of the relevant genes and proteins. Here we discuss unequivocal evidence of roles for the murine Cyp4a14, Cyp4a10, and Cyp2c44 genes in the pathophysiology of hypertension by showing that: (a) Cyp4a14(-/-) mice develop sexually dimorphic hypertension associated with renal vasoconstriction, and up-regulated expression of Cyp4a12a and pro-hypertensive 20-hydroxyeicosatetraenoic acid (20-HETE) levels, and b) Cyp4a10(-/-) and Cyp2c44(-/-) mice develop salt sensitive hypertension linked to downregulation or lack of the Cyp2c44 epoxygenase, reductions in anti-hypertensive epoxyeicosatrienoic acids (EETs), and increases in distal sodium reabsorption. Based on these studies, the human CYP4A11 and CYPs 2C8 and 2C9 genes and their products are identified as potential candidates for studies of the molecular basis of human hypertension.

Cytochrome 4A11 Genetic Polymorphisms Increase Susceptibility to Ischemic Stroke and Associate with Atherothrombotic Events After Stroke in Chinese

To evaluate the associations between four single-nucleotide polymorphisms (SNPs) in CYP4A11 and CYP4F2 and ischemic stroke (IS), and between these variants and atherothrombotic events after stroke. IS patients (n=396) and controls (n=378) were genotyped for two CYP4A11 SNPs (rs2269231 and rs9333025) and two CYP4F2 SNPs (rs2108622 and rs3093135). Patients were followed up for 12 months after the stroke for the atherothrombotic events. The frequency of the rs9333025 GG genotype was significantly higher in IS patients than in controls. Logistic regression analysis showed that the presence of rs9333025 GG in patients was associated with significantly higher risk of IS. Cox regression analysis revealed that the rs9333025 GG genotype was an independent risk factor for atherothrombotic events after stroke. The rs9333025 GG genotype increases patients' susceptibility to IS and is associated with high frequencies of atherothrombotic events in stroke patients.

Cytochrome P450 eicosanoids in hypertension and renal disease

PURPOSE OF REVIEW

Cytochrome (CYP) P450 metabolites of arachidonic acid, 20-hydroxyeicosatetraenoic acid (20-HETE) and epoxyeicosatrienoic acids (EETs) contribute to the regulation of renal tubular and vascular function. This review highlights the results of the recent genetic studies in humans and rodent models, indicating that these eicosanoids participate in the control of blood pressure (BP), chronic kidney disease (CKD), renal ischemia-reperfusion injury (IRI) and polycystic kidney disease (PKD).

RECENT FINDINGS

Endogenous 20-HETE has been reported to play an essential role in the myogenic and tubuloglomerular feedback responses in the afferent arteriole, and a deficiency of 20-HETE contributes to the development of hypertension and renal injury in Dahl S rats. Mutations in CYP4A11 and CYP4F2 have been linked to elevated BP in humans. EETs have been shown to regulate epithelial sodium channel in the collecting duct, lower BP and have renoprotective properties. 20-HETE also opposes the development of CKD and IRI, and may play a role in PKD.

SUMMARY

These studies indicate that CYP P450 metabolites of arachidonic acid play an important role in the control of BP, CKD, AKI and PKD. Drugs targeting these pathways could be useful in the treatment of IRI and CKD.