Emerging Roles and Therapeutic Applications of Arachidonic Acid Pathways in Cardiometabolic Diseases

Cardiometabolic disease has become a major health burden worldwide, with sharply increasing prevalence but highly limited therapeutic interventions. Emerging evidence has revealed that arachidonic acid derivatives and pathway factors link metabolic disorders to cardiovascular risks and intimately participate in the progression and severity of cardiometabolic diseases. In this review, we systemically summarized and updated the biological functions of arachidonic acid pathways in cardiometabolic diseases, mainly focusing on heart failure, hypertension, atherosclerosis, nonalcoholic fatty liver disease, obesity, and diabetes. We further discussed the cellular and molecular mechanisms of arachidonic acid pathway-mediated regulation of cardiometabolic diseases and highlighted the emerging clinical advances to improve these pathological conditions by targeting arachidonic acid metabolites and pathway factors.

Genetics of ischemic stroke functional outcome

Ischemic stroke, which accounts for 87% of cerebrovascular accidents, is responsible for massive global burden both in terms of economic cost and personal hardship. Many stroke survivors face long-term disability-a phenotype associated with an increasing number of genetic variants. While clinical variables such as stroke severity greatly impact recovery, genetic polymorphisms linked to functional outcome may offer physicians a unique opportunity to deliver personalized care based on their patient's genetic makeup, leading to improved outcomes. A comprehensive catalogue of the variants at play is required for such an approach. In this review, we compile and describe the polymorphisms associated with outcome scores such as modified Rankin Scale and Barthel Index. Our search identified 74 known genetic polymorphisms spread across 48 features associated with various poststroke disability metrics. The known variants span diverse biological systems and are related to inflammation, vascular homeostasis, growth factors, metabolism, the p53 regulatory pathway, and mitochondrial variation. Understanding how these variants influence functional outcome may be helpful in maximizing poststroke recovery.

Dickkopf-1 promotes vascular smooth muscle cell foam cell formation and atherosclerosis development through CYP4A11/SREBP2/ABCA1

Vascular smooth muscle cells (VSMCs) are considered to be a crucial source of foam cells in atherosclerosis due to their low expression level of cholesterol exporter ATP-binding cassette transporter A1 (ABCA1) intrinsically. While the definite regulatory mechanisms are complicated and have not yet been fully elucidated, we previously reported that Dickkopf-1 (DKK1) mediates endothelial cell (EC) dysfunction, thereby aggravating atherosclerosis. However, the role of smooth muscle cell (SMC) DKK1 in atherosclerosis and foam cell formation remains unknown. In this study, we established SMC-specific DKK1-knockout (DKK1SMKO ) mice by crossbreeding DKK1flox/flox mice with TAGLN-Cre mice. Then, DKK1SMKO mice were crossed with APOE-/- mice to generate DKK1SMKO /APOE-/- mice, which exhibited milder atherosclerotic burden and fewer SMC foam cells. In vitro loss- and gain-of-function studies of DKK1 in primary human aortic smooth muscle cells (HASMCs) have proven that DKK1 prevented oxidized lipid-induced ABCA1 upregulation and cholesterol efflux and promoted SMC foam cell formation. Mechanistically, RNA-sequencing (RNA-seq) analysis of HASMCs as well as chromatin immunoprecipitation (ChIP) experiments showed that DKK1 mediates the binding of transcription factor CCAAT/enhancer-binding protein delta (C/EBPδ) to the promoter of cytochrome P450 epoxygenase 4A11 (CYP4A11) to regulate its expression. In addition, CYP4A11 as well as its metabolite 20-HETE-promoted activation of transcription factor sterol regulatory element-binding protein 2 (SREBP2) mediated the DKK1 regulation of ABCA1 in SMC. Furthermore, HET0016, the antagonist of CYP4A11, has also shown an alleviating effect on atherosclerosis. In conclusion, our results demonstrate that DKK1 promotes SMC foam cell formation during atherosclerosis via a reduction in CYP4A11-20-HETE/SREBP2-mediated ABCA1 expression.

Role of CYP19A1 Loci (rs28757157 and rs3751591) with Ischemic Stroke Risk in the Chinese Han Population

Introduction

Ischemic stroke (IS) is a multifactorial and polygenic disease, which is affected by genetic factors. In this study, we explored the role of CYP19A1 single nucleotide polymorphisms (SNPs) in IS in the Chinese population.

Methods

1302 subjects (651 controls and 651 cases) were recruited in this case-control study. Four candidate SNPs (rs28757157 C/T, rs3751592 C/T, rs3751591 G/A, rs59429575 C/T) of CYP19A1 were selected by the 1000 genomes project database. The association between CYP19A1 SNPs and IS risk was assessed using logistic regression analysis with odds ratio (OR) and 95% confidence intervals (CIs). False-positive report probability (FPRP) analysis further verified the positive results. The interaction of SNP-SNP was analyzed by multi-factor dimensionality reduction (MDR) to predict is risk.

Results

In the research, CYP19A1 loci (rs28757157 and rs3751591) were associated with the occurrence of IS. The two variants conferred an increased susceptibility to IS in the subjects aged over 60 years old, smokers and drinkers. Rs28757157 was related to the risk of IS in females, non-smokers and subjects with BMI less than 24, while rs59429575 was related to the risk of IS in males and subjects with BMI greater than 24.

Conclusion

The study revealed that there is a significant association between CYP19A1 loci (rs28757157 and rs3751591) and IS risk in the Chinese Han population, providing a theoretical basis for further exploring its specific role in the pathogenesis of IS.

Variants in genes related to inflammation and endothelial function can increase the risk for carotid atherosclerosis in southwestern China

Aim

To investigate the potential association between polymorphisms in genes involved in endothelial function, inflammation and carotid atherosclerosis.

Methods

This was a three-center, population-based sectional survey conducted in Sichuan province of southwestern China. We randomly selected 8 different communities in Sichuan, and the residents in each community volunteered to participate in the survey by face-to-face questionnaire. A total of 2,377 residents with high stroke risk population in the 8 communities were included. Carotid atherosclerosis was evaluated by carotid ultrasound, and the 19 single nucleotide polymorphisms (SNPs) in 10 endothelial function as well as inflammation relevant genes were measured in the high stroke risk population. Carotid atherosclerosis was defined by the presence of carotid plaque or any carotid stenosis ≥15% or mean intima-media thickness (IMT) > 0.9 mm. Generalized multifactor dimensionality reduction (GMDR) approach was used to analyze gene-gene interactions among the 19 SNPs.

Results

Among the 2,377 subjects with high stroke risk, 1,028 subjects had carotid atherosclerosis (43.2%), of which 852 (35.8%) cases had carotid plaque, 295 (12.4%) cases had ≥15% carotid stenosis, whereas 445 (18.7%) had mean IMT > 0.9 mm. Multivariate logistic regression revealed that IL1A rs1609682 TT and HABP2 rs7923349 TT served as independent risk factors for carotid atherosclerosis (OR, 1.45, 95% CI: 1.034-2.032, p = 0.031, and OR, 1.829, 95% CI: 1.228-2.723, p = 0.003). GMDR analysis indicated that there was a significant gene-gene interaction found among IL1A rs1609682, ITGA2 rs1991013, and HABP2 rs7923349. After adjusting the covariates, the high-risk interactive genotypes in the 3 variants were significantly associated with a significantly higher risk for carotid atherosclerosis (OR, 2.08, 95% CI: 1.257-5.98, p < 0.001).

Conclusion

The prevalence of carotid atherosclerosis was observed to be extremely high in the high-risk stroke population in southwestern China. There were associations observed between the specific variants in inflammation and endothelial function relevant genes and carotid atherosclerosis. The high-risk interactive genotypes among IL1A rs1609682, ITGA2 rs1991013, and HABP2 rs7923349 significantly increased the risk of carotid atherosclerosis. These results are expected to provide novel strategies for the prevention of carotid atherosclerosis. The gene-gene interactive analysis used in this study may be very helpful to elucidate complex genetic risk factors for carotid atherosclerosis.

Inflammation and endothelial function-related gene polymorphisms are associated with carotid atherosclerosis-A study of community population in Southwest China

OBJECTIVES

To investigate the relationships between 18 single nucleotide polymorphisms with carotid atherosclerosis and whether interactions among these genes were associated with an increased risk of carotid atherosclerosis.

METHODS

Face-to-face surveys were conducted with individuals aged 40 or older in eight communities. A total of 2377 individuals were included in the study. Ultrasound was used to detect carotid atherosclerosis in the included population. 18 loci of 10 genes associated with inflammation and endothelial function were detected. Gene-gene interactions were analyzed using generalized multifactor dimensionality reduction (GMDR).

RESULTS

Among the 2377 subjects, 445 (18.7%) subjects had increased intima-media thickness in the common carotid artery (CCA-IMT), and 398 (16.7%) subjects were detected with vulnerable plaque. In addition, NOS2A rs2297518 polymorphism was associated with increased CCA-IMT, IL1A rs1609682, and HABP2 rs7923349 polymorphisms were associated with vulnerable plaque. Besides, GMDR analysis showed significant gene-gene interactions among TNFSF4 rs1234313, IL1A rs1609682, TLR4 rs1927911, ITGA2 rs1991013, NOS2A rs2297518, IL6R rs4845625, ITGA2 rs4865756, HABP2 rs7923349, NOS2A rs8081248, HABP2 rs932650.

CONCLUSION

The prevalences of increased CCA-IMT and vulnerable plaque were high in Southwestern China's high-risk stroke population. Furthermore, inflammation and endothelial function-related gene polymorphisms were associated with carotid atherosclerosis.

Research progress on the protective mechanism of a novel soluble epoxide hydrolase inhibitor TPPU on ischemic stroke

Arachidonic Acid (AA) is the precursor of cerebrovascular active substances in the human body, and its metabolites are closely associated with the pathogenesis of cerebrovascular diseases. In recent years, the cytochrome P450 (CYP) metabolic pathway of AA has become a research hotspot. Furthermore, the CYP metabolic pathway of AA is regulated by soluble epoxide hydrolase (sEH). 1-trifluoromethoxyphenyl-3(1-propionylpiperidin-4-yl) urea (TPPU) is a novel sEH inhibitor that exerts cerebrovascular protective activity. This article reviews the mechanism of TPPU's protective effect on ischemic stroke disease.

Inflammation and endothelial function relevant genetic polymorphisms in carotid stenosis in southwestern China

Aim

To evaluate the relationship between carotid stenosis with variants in genes referred to inflammation and endothelial function.

Methods

There was a multi-center, cross sectional survey in southwestern China. The eight communities were selected at random in southwestern China. The residents aged ≥40 years volunteered to participate in face-to-face survey. Subjects with at least three of the aforementioned eight stroke related risk factors or a history of stroke were classified as high-risk population for stroke. A total of 2,377 subjects were the high-risk population for stroke in the eight communities, and degree of carotid stenosis was assessed by carotid ultrasound. Genotypes of 6 variants in 3 genes related to inflammation and endothelial function were examined. Gene-gene interaction was analyzed by generalized multifactor dimensionality reduction (GMDR).

Results

Carotid stenosis were found in 295 (12.41%) subjects, of whom 51 (17.29%) had moderate or severe stenosis. According to multivariate logistic regression analysis, we found that HABP2rs7923349TT was independent risk factor for carotid stenosis (OR, 1.96, 95% CI: 1.22-3.13, P = 0.005) and ITGA2rs1991013AG and HABP2rs7923349TT were independent risk factors for moderate to severe carotid stenosis (OR, 2.28, 95% CI: 1.28-4.07, P = 0.005; OR, 2.90, 95% CI: 1.19-7.08, P = 0.019). GMDR analysis showed that there was a significant gene-gene interaction between ITGA2 rs4865756 and HABP2 rs7923349, and the high-risk interactive genotype in the two variants was independently associated with a higher risk for carotid stenosis after adjusting the covariates (OR,1. 42, 95% CI 1.10-1.84, P = 0.008).

Conclusions

Prevalence of carotid stenosis was very high in the high-risk stroke population in southwestern China. Variants in genes referred in endothelial function were associated with the carotid stenosis. The high-risk interactive genotype in ITGA2 rs4865756 and HABP2 rs7923349 was independently associated with a higher risk for carotid stenosis.

Prevalence and Risk Factors of High-Risk Population for Stroke: A Population-Based Cross-Sectional Survey in Southwestern China

With the aging of the population and the change of lifestyle in China, the prevalence and risk factors of the high-risk population for stroke may change. However, few studies performed community-based high-risk stroke population surveys in China. Hence, we performed this multicenter, cross-sectional, and community-based survey in Sichuan of southwestern China, according to the China National Stroke Screening Survey (CNSSS) program in 2015. The residents aged ≥ 40 years volunteered to participate in the face-to-face survey in 8 communities in Sichuan. The 8 communities were selected using the cluster randomization method. Subjects with at least three of the eight stroke-related risk factors were classified as a high-risk population for stroke. Otherwise were classified as a low-risk population for stroke. Furthermore, 1,011 individuals were randomly selected among the low-risk population for stroke as controls. Among 16,892 participants, 2,369 (14.0%) were high-risk population for stroke. After full adjustments, all eight risk factors for stroke were significantly associated with the high-risk population for stroke (P < 0.001). The largest contributor was hypertension [population-attributable risk (PAR) 28.4%], followed by physical inactivity (PAR 14.2%), dyslipidemia (PAR 11.2%), overweight/obesity (PAR 9.4%), diabetes (PAR 7.2%), family history (PAR 6.8%), smoking (PAR 5.9%), and atrial fibrillation (PAR 3.5%). Carotid atherosclerosis was more serious in the high-risk population for stroke than in controls (P < 0.05). The prevalence of the high-risk population for stroke was high in southwestern China. Hypertension, physical inactivity, and dyslipidemia were stronger contributors for the high-risk population for stroke. Individual-level and population-level interventions for these leading risk factors are very important for the primary prevention of stroke.

1-trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl) Urea Exerts Neuro-Protective Effects Against Ischemic Injury via Suppressing JNK/p38 MAPK-Mediated Mitochondrial Apoptosis Pathway

BACKGROUND

1-trifluoromethoxyphenyl-3-(1- propionylpiperidin-4-yl) urea (TPPU) is a novel soluble epoxide hydrolase inhibitor which can protect against cerebral ischemic injury in middle cerebral artery occlusion rat model. However, the effects and potential mechanisms of TPPU on mitochondrial dysfunction are poorly understood.

MATERIALS AND METHODS

In oxygen-glucose deprivation/reperfusion (OGD/R)-induced cortical neurons, the effect of TPPU on cell viability was measured by MTT assay and apoptosis was evaluated using TUNEL assay. Mitochondria were observed by transmission electron microscopy and Mitotracker green staining assay, mitochondrial membrane potential was determined by JC-1 staining assay, activities of mitochondrial respiratory chain complexes (MRCC) I-IV and ATPase were measured by MRCC Activity Assay Kits and spectrophotometer. Western blot was used to investigate the effects of TPPU on apoptosis-related proteins.

RESULTS

TPPU treatment demonstrated significant protective effect on the OGD/R-induced cortical neurons by reducing cell death and number of apoptotic cells, stabilizing mitochondrial ultrastructure and morphology, increasing mitochondrial membrane potential and activities of MRCC I-IV and ATPase. Furthermore, TPPU treatment might effectively reverse the upregulation of caspase-3, Bax, p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal protein kinase (JNK), alleviate the inhibition of Bcl-2 in OGD/R-induced cortical neurons.

CONCLUSIONS

TPPU exerts a marked neuroprotective effect against mitochondrial dysfunction after cerebral ischemia potentially via suppressing JNK/p38 MAPK-mediated mitochondrial apoptosis signal pathway, it may be a promising neuroprotective agent for cerebral ischemia.

Vulnerable Plaque Is More Prevalent in Male Individuals at High Risk of Stroke: A Propensity Score-Matched Study

OBJECTIVES

To assess the gender differences in the prevalence of carotid vulnerable plaques in high-risk individuals for stroke in a multicenter, cross-sectional study.

METHODS

In the year 2015, 18595 residents who were at the age of 40 or older participated in a face-to-face study in eight communities in southwestern China. Totally 2,644 participants at high risk of stroke were enrolled. Before and after propensity score matching (PSM), the prevalence of carotid plaques and vulnerable plaques were compared between men and women. Multivariate analyses were applied to explore the association between the gender and carotid plaques. Stratified analyses and interaction tests were performed to identify factors that might modify the association between the gender and carotid plaques.

RESULTS

Among 2644 high-risk individuals enrolled, there were 1,202 (45.5%) men and 1442 (54.5%) women. Carotid plaques were detected in 904 (34.2%) participants, while vulnerable plaques were found in 425 (16.1%) participants. Before PSM, carotid plaques were more prevalent in male individuals than the female (36.7% vs. 32.1%, p = 0.01), as well as vulnerable plaque (20.0% vs. 12.8%, p < 0.01). Men tend to have a higher prevalence of vulnerable plaques in multivariate analyses (adjusted OR 1.70, 95% CI 1.10-2.62, p = 0.02). Stratified analyses and interaction tests demonstrated that the association between male sex and vulnerable carotid plaque did not change by age, family history of stroke, histories of chronic disease, smoking status, drinking status, physical activity, and BMI (all p for interaction > 0.05). After PSM, vulnerable plaques were still more prevalent in male individuals than the female (17.03% vs. 12.07%, p = 0.032).

CONCLUSION

Male individuals had a higher risk of vulnerable carotid plaque independent of classical vascular risk factors. Whether there is a gender-specific association between variations in genes related to inflammation, lipid metabolis, and endothelial function and plaque vulnerability needs to be further studied.

The influence of CYP1A1 and CYP1A2 polymorphisms on stroke risk in the Chinese population

Backgrounds

Stroke is a sudden disorder of cerebral blood circulation. Many studies have illustrated that dyslipidemia, hypertension, diabetes, smoking and excessive drinking are the traditional risk factors for stroke. This study aimed to observe the relationship between CYP1A1 and CYP1A2 variants and stroke risk in the Chinese population.

Methods

Agena MassARRAY Assay was used to genotype four single nucleotide polymorphisms (SNPs) in 477 cases and 480 controls. The chi-square test and logistic-regression analysis were used to explore the relationship between CYP1A1 and CYP1A2 variants and stroke risk.

Results

Individuals with CYP1A2 rs762551 C was associated with a lower risk of stroke than that of allele A. Age stratification analysis showed that rs762551 was only observed to be associated with a lower risk of stroke in ≤64ys age group. After gender stratification analysis, a significant association between rs762551 and stroke risk was found in males, but not in females. The four SNPs were found to be correlated with stroke risk in patients with hypertension, coronary heart disease, cerebral infarction and lacunar infarction.

Conclusion

In this study, the results first showed that CYP1A1 and CYP1A2 variants were associated with stroke risk. Larger and well-designed studies are needed to confirm the results.

Protective Effects of the Soluble Epoxide Hydrolase Inhibitor 1-Trifluoromethoxyphenyl-3-(1-Propionylpiperidin-4-yl) Urea in a Rat Model of Permanent Middle Cerebral Artery Occlusion

Acute ischemic stroke is a serious disease that endangers human health. In our efforts to develop an effective therapy, we previously showed that the potent, highly selective inhibitor of soluble epoxide hydrolase called 1-trifuoromethoxyphenyl-3-(1-propionylpiperidin-4-yl) urea (TPPU) protects the brain against focal ischemia in rats. Here we explored the mechanism of TPPU action by assessing whether it could preserve blood-brain barrier integrity and reduce apoptosis in the brain during permanent middle cerebral artery occlusion in male Sprague-Dawley rats. TPPU administration at the onset of stroke and once daily thereafter led to smaller infarct volume and brain edema as well as milder neurological deficits. TPPU significantly inhibited the activity of soluble epoxide hydrolase and matrix metalloproteases 2 and 9, reducing 14,15-DHET levels, while increasing expression of tight junction proteins. TPPU decreased numbers of apoptotic cells by down-regulating the pro-apoptotic proteins BAX and Caspase-3, while up-regulating the anti-apoptotic protein BCL-2. Our results suggest that TPPU can protect the blood-brain barrier and reduce the apoptosis of brain tissue caused by ischemia.

Inflammation and Endothelial Function Relevant Genetic Polymorphisms and Carotid Plaque in Chinese Population

Aim: To examine the association between carotid plaque and variants in genes involved in inflammation and endothelial function.

Methods: This was a multicenter, cross-sectional survey in southwestern China. The residents aged ≥ 40 years volunteered to participate in the face-to-face survey in eight communities. A total of 2,377 subjects with high stroke risk were enrolled. Carotid plaque and plaque phenotype were assessed by carotid ultrasound. Genotypes of 19 variants in 10 genes related to inflammation and endothelial function were examined. Gene-gene interaction was analyzed by generalized multifactor dimensionality reduction (GMDR).

Results: Carotid plaques were found in 852 (35.8%) subjects, and 454 (53.3%) had stable plaques, whereas 398 (46.7%) had vulnerable plaques. PPARA rs4253655, HABP2 rs7923349, and IL1A rs1609682 were associated with the presence of carotid plaque, and NOS2A rs2297518 and PPARA rs4253655 were associated with vulnerable plaque in univariate analysis. The GMDR analysis revealed that there was a significant gene–gene interaction among HABP2 rs7923349, ITGA2 rs1991013, IL1A rs1609682, and NOS2A rs8081248, and the high-risk interactive genotype among the four variants was independently associated with a higher risk of carotid vulnerable plaque after adjusting the covariates (OR, 2.86, 95% CI: 1.32–7.13, P = 0.003).

Conclusion: The prevalence of carotid plaque was very high in the high-risk stroke population in southwestern China. Variants in genes involved in the endothelial function and inflammation were associated with the carotid plaque. The high-risk interactive genotype among rs7923349, rs1991013, rs1609682, and rs8081248 was independently associated with a higher risk of vulnerable plaque.

Conflicting Roles of 20-HETE in Hypertension and Stroke

Hypertension is the most common modifiable risk factor for stroke, and understanding the underlying mechanisms of hypertension and hypertension-related stroke is crucial. 20-hydroxy-5, 8, 11, 14-eicosatetraenoic acid (20-HETE), which plays an important role in vasoconstriction, autoregulation, endothelial dysfunction, angiogenesis, inflammation, and blood-brain barrier integrity, has been linked to hypertension and stroke. 20-HETE can promote hypertension by potentiating the vascular response to vasoconstrictors; it also can reduce blood pressure by inhibition of sodium transport in the kidney. The production of 20-HETE is elevated after the onset of both ischemic and hemorrhagic strokes; on the other hand, subjects with genetic variants in CYP4F2 and CYP4A11 that reduce 20-HETE production are more susceptible to stroke. This review summarizes recent genetic variants in CYP4F2, and CYP4A11 influencing 20-HETE production and discusses the role of 20-HETE in hypertension and the susceptibility to the onset, progression, and prognosis of ischemic and hemorrhagic strokes.

Targeted metabolomic approach in men with carotid plaque

Background

The aim of the study was to analyse the presence of several metabolites related to atherosclerosis in the plasma of patients with unstable carotid plaque and in the plasma of healthy subjects.

Materials and methods

We included 20 patients who had undergone carotid endarterectomy and 20 healthy subjects as a control group. All the subjects recruited were male. We used a metabolomic approach with liquid chromatography coupled to mass spectrometry to evaluate plasma metabolite levels in the metabolic pathway involved in the progression of atherosclerotic plaque.

Results

We observed that circulating levels of 20-HETE were significantly higher in patients with atheroma plaque than in healthy subjects (p = 0.018). No differences were found with regard to the other metabolites analysed. We also conducted a random forest analysis and found that 20-HETE was the main differentiator in the list of selected metabolites. In addition, plasma levels of 20-HETE correlated positively with body mass index (r = 0.427, p = 0.007) and diastolic blood pressure (r = 0.365, p = 0.028).

Conclusion

This study confirms that of all the molecules studied only 20-HETE is related to carotid plaque. Further studies are needed to compare patients with stable carotid plaque vs. patients with unstable carotid plaque in order to confirm that 20-HETE could be a potential factor related to carotid plaque.

Detrimental Effects of Testosterone Addition to Estrogen Therapy Involve Cytochrome P-450-Induced 20-HETE Synthesis in Aorta of Ovariectomized Spontaneously Hypertensive Rat (SHR), a Model of Postmenopausal Hypertension

Postmenopausal period has been associated to different symptoms such as hot flashes, vulvovaginal atrophy, hypoactive sexual desire disorder (HSDD) and others. Clinical studies have described postmenopausal women presenting HSDD can benefit from the association of testosterone to conventional hormonal therapy. Testosterone has been linked to development of cardiovascular diseases including hypertension and it also increases cytochrome P-450-induced 20-HETE synthesis which in turn results in vascular dysfunction. However, the effect of testosterone plus estrogen in the cardiovascular system is still very poorly studied. The aim of the present study is to evaluate the role of cytochrome P-450 pathway in a postmenopausal hypertensive female treated with testosterone plus estrogen. For that, hypertensive ovariectomized rats (OVX-SHR) were used as a model of postmenopausal hypertension and four groups were created: SHAM-operated (SHAM), ovariectomized SHR (OVX), OVX treated for 15 days with conjugated equine estrogens [(CEE) 9.6 μg/Kg/day/po] or CEE associated to testosterone [(CEE+T) 2.85 mg/kg/weekly/im]. Phenylephrine-induced contraction and generation of reactive oxygen species (ROS) were markedly increased in aortic rings from OVX-SHR compared to SHAM rats which were restored by CEE treatment. On the other hand, CEE+T abolished vascular effects by CEE and augmented both systolic and diastolic blood pressure of SHR. Treatment of aortic rings with the CYP/20-HETE synthesis inhibitor HET0016 (1 μM) reduced phenylephrine hyperreactivity and the augmented ROS generation in the CEE+T group. These results are paralleled by the increased CYP4F3 protein expression and activity in aortas of CEE+T. In conclusion, we showed that association of testosterone to estrogen therapy produces detrimental effects in cardiovascular system of ovariectomized hypertensive females via CYP4F3/20-HETE pathway. Therefore, our findings support the standpoint that the CYP/20-HETE pathway is an important therapeutic target for the prevention of cardiovascular disease in menopausal women in the presence of high levels of testosterone.

Interactions among variants in TXA2R, P2Y12 and GPIIIa are associated with carotid plaque vulnerability in Chinese population

PURPOSE

The associations between variants in platelet activation-relevant genes and carotid plaque vulnerability are not fully understood. The aim of the present study was to investigate the associations of the variants in platelet activation-relevant genes and interactions among these variants with carotid plaque vulnerability.

RESULTS

There were no significant differences in the frequencies of genotypes of the 11 variants between patients and controls. Among 396 patients, 102 patients had not carotid plaque, 106 had VP, and 188 had SP. The 11 variants were not independently associated with risk of carotid plaque vulnerability after adjusting for potential confounding variables. However, the GMDR analysis showed that there were synergistic effects of gene-gene interactions among TXA2Rr s1131882, GPIIIa rs2317676 and P2Y12 rs16863323 on carotid plaque vulnerability. The high-risk interactions among the three variants were associated with high platelet activation, and independently associated with the risk of carotid plaque vulnerability.

METHODS

Eleven variants in platelet activation-relevant genes were examined using mass spectrometry methods in 396 ischemic stroke patients and 291controls. Platelet-leukocyte aggregates and platelet aggregation were also measured. Carotid plaques were assessed by B-mode ultrasound. According to the results of ultrasound, the patients were stratified into three groups: non-plaque group, vulnerable plaque (VP) group and stable plaque (SP) group. Furthermore, gene-gene interactions were analyzed using generalized multifactor dimensionality reduction (GMDR) methods.

CONCLUSIONS

The rs1131882, rs2317676, and rs16863323 three-loci interactions may confer a higher risk of carotid plaque vulnerability, and might be potential markers for plaque instability.

Associations between thromboxane A synthase 1 gene polymorphisms and the risk of ischemic stroke in a Chinese Han population

Thromboxane A synthase 1 (TBXAS1) catalyses the synthesis of thromboxane A2 (TXA2), which plays an important role in the pathogenesis of ischemic stroke. Thus, the TBXAS1 gene was investigated as a candidate gene involved in the formation of atherosclerosis. This case-control study collected peripheral blood specimens and clinical data of 370 ischemic stroke patients and 340 healthy controls in the Northern Chinese Han population from October 2010 to May 2011. Two TBXAS1 single-nucleotide polymorphisms, rs2267682 and rs10487667, were analyzed using a SNaPshot Multiplex sequencing assay to explore the relationships between the single-nucleotide polymorphisms in TBXAS1 and ischemic stroke. The TT genotype frequency and T allele frequency of rs2267682 in the patients with ischemic stroke were significantly higher than those in the controls (P < 0.01 and P = 0.02). Furthermore, compared with the GG + GT genotype, the TT rs2267682 genotype was associated with increased risk of ischemic stroke (odds ratio (OR) = 1.80, 95% confidence interval (CI): 1.16–2.79, P < 0.01). Multivariate logistic analysis with adjustments for confounding factors revealed that rs2267682 was still associated with ischemic stroke (OR = 1.94, 95% CI : 1.13–3.33, P = 0.02). The frequency of the T-G haplotype in the patients was significantly higher than that in the controls according haplotype analysis (OR = 1.49, 95% CI: 1.10–2.00, P < 0.01). These data reveal that the rs2267682 TBXAS1 polymorphism is associated with ischemic stroke. The TT genotype of TBXAS1 and T allele of rs2267682 increase susceptibility to ischemic stroke in this Northern Chinese Han population. The protocol has been registered with the Chinese Clinical Trial Registry (registration number: ChiCTR-COC-17013559).

Epoxyeicosatrienoic Acids are Mediated by EPHX2 Variants and may be a Predictor of Early Neurological Deterioration in Acute Minor Ischemic Stroke

Aim: To investigatethe association of plasma epoxyeicosatrienoic acids (EETs) with early neurologic deterioration (END), and whether EETs are mediated by EPHX2 variants in patients with minor ischemic stroke (MIS).

Method: This was a prospective, multi-center observational study in patients with acute MIS in the Chinese population.Plasma EETs levels were measured on admission. Single nucleotide polymorphisms (SNPs) of EPHX2rs751141 were genotyped using mass spectrometry. The primary outcome was END within 10 days after admission. END was defined as an increase in NIHSS of 2 or more points. The degree of disability was assessed using the modified Rankin Scale (mRS) at 3 months after admission.

Results: A total of 322 patients were enrolled, of which 85 patients (26.4%) experienced END. The mean EETs level was 64.1 ± 7.5 nmol/L. EETs levels were significantly lower in patients with END compared to patients without END. Frequency of EPHX2 rs751141 GG was higher in patients with END than in patients without END, and EPHX2 rs751141 GG genotype was associated with lower EETs levels. Low level (< 64.4 nmol/L) of EETs was an independent predictor of END (first and second quartiles) in multivariate analyses. END was associated with a higher risk of poor outcome (mRS scores 3–6) at 3 months.

Conclusion: END is fairly common and associated with poor outcomes in acute MIS. EPHX2 variants may mediate EETs levels, and low levels of EETs may be a predictor for END in acute MIS.

Variants in COX-2, PTGIS, and TBXAS1 Are Associated with Carotid Artery or Intracranial Arterial Stenosis and Neurologic Deterioration in Ischemic Stroke Patients

BACKGROUND

Eicosanoids may play a role in ischemic stroke (IS). However, the association of variants in eicosanoid genes with symptomatic carotid artery or intracranial arterial stenosis and neurologic deterioration (ND) is not fully understood. The aim of the present study was to investigate the association of 11 variants in eicosanoid genes with symptomatic carotid artery or intracranial arterial stenosis and ND.

METHODS

Eleven variants in eicosanoid genes were examined using mass spectrometry method in 297 IS patients. The symptomatic carotid artery or intracranial arterial stenosis was assessed by computed tomographic angiography. Platelet aggregation and platelet-leukocyte aggregates were measured. The primary outcome was ND within 10 days of admission. ND was defined as an increase of 2 or more points in National Institutes of Health Stroke Scale score.

RESULTS

Among 297 IS patients, 182 (61.3%) cases had symptomatic carotid artery or intracranial arterial stenosis, and 88 (29.6%) patients experienced ND within 10 days after admission. Symptomatic carotid artery or intracranial arterial stenosis was significantly associated with higher ND (P < .001). Rs20417CC, rs41708TT, and rs5629CC were independent risk factors for symptomatic carotid artery or intracranial arterial stenosis and ND, and associated with higher platelet aggregation and platelet-leukocyte aggregates.

CONCLUSIONS

Symptomatic carotid artery or intracranial arterial stenosis was associated with higher ND. Rs20417CC, rs41708TT, and rs5629CC were not only independent risk factors for symptomatic carotid artery or intracranial arterial stenosis, but also independent risk predictors for ND.

Genetic variants of PTGS2, TXA2R and TXAS1 are associated with carotid plaque vulnerability, platelet activation and TXA2 levels in ischemic stroke patients

Eicosanoids may play a role in ischemic stroke. However, the associations of variants in cyclooxygenase (COX) pathway genes and interaction among these variants with carotid plaque vulnerability are not fully understood. In present study, twelve variants in COX pathway genes were examined using matrix-assisted laser desorption ionization time-of-flight mass spectrometry method in 396 patients with ischemic stroke and 291 controls. Platelet aggregation, platelet-leukocyte aggregates, and urine 11-dehydrothromboxane B2 (11-dTxB2) were also measured. According to the results of carotid high-resolution B-mode ultrasound, the patients were stratified into the following groups [i.e., non-carotid plaque and carotid plaque. The carotid plaque was further classified into subgroups of echolucent plaque (ELP) and echogenic plaque (EGP)]. Additionally, gene-gene interactions were analyzed to assess whether there was any interactive role for assessed variants in affecting carotid plaque vulnerability, platelet activation and 11-dTxB2 levels. There were no significant differences in the frequencies of genotypes of the twelve variants between patients and controls. Among 396 patients, 294 cases (74.2%) had carotid plaques (106 had ELP, 188 had EGP). Frequency of PTGS2 rs20417CC, TXAS1 rs2267679TT, TXAS1 rs41708TT, PTGIS rs5602CC, and TXA2R rs1131882TT genotype was significantly higher in patients with plaque compared with patients without plaque, or in patients with ELP compared with patients with EGP. 11-dTxB2 levels, platelet aggregation and platelet-leukocyte aggregates were significantly higher in patients with ELP compared with patients without plaque or with EGP. Multivariate logistic regression analysis revealed that PTGS2 rs20417CC, TXA2R rs1131882TT, and high-risk interaction among variants in PTGS2 rs20417, TXA2R rs1131882 and TXAS1 rs41708 were independently associated with the risk of ELP after adjusting for confounding variables. The variants in COX pathway genes and the high-risk interactions among variants in PTGS2 rs20417, TXA2R rs1131882 and TXAS1 rs41708 were associated with high 11-dTxB2 and platelet activation, and independently associated with the risk of carotid plaque vulnerability. These variants might be potential markers for plaque instability.

CYP Genetic Variants, CYP Metabolite Levels, and Neurologic Deterioration in Acute Ischemic Stroke in Chinese Population

BACKGROUND

The mechanisms of neurologic deterioration (ND) are not fully understood. The aim of the present study was to evaluate the relationship between CYP genetic variants and CYP metabolite levels with ND in acute ischemic stroke patients.

METHODS

Eleven single nucleotide polymorphisms (SNPs) of seven CYP genes were genotyped in 396 patients with acute ischemic stroke. The CYP plasma metabolite levels (20-hydroxyeicosatetraenoic acid [HETE], total epoxyeicosatrienoic acids [EETs], and dihydroxyeicosatrienoic acids [DiHETEs]) were also assessed. The primary outcome was ND within 10 days on admission. ND was defined as an increase of two or more points in the National Institutes of Health Stroke Scale score.

RESULTS

Among 396 patients, 101 patients (25.5%) experienced ND. The plasma levels of 20-HETE and DiHETEs were significantly higher and the EET levels were significantly lower in patients with ND compared to patients without ND. Univariate analyses revealed that old age, diabetes mellitus (DM), higher fasting glucose, and higher hemoglobin A1c (HbA1c) were associated with ND. CYP2C8 rs17110453 CC, EPHX2 rs751141 GG, and CYP4A11 rs9333025 GG were independently associated with ND after adjusting age, DM, fasting glucose, and HbA1c (odds ratio [OR]: 1.60, 95% confidence interval [CI]: 1.02-3.72; OR: 3.01, 95% CI: 1.29-7.13; OR: 2.75, 95% CI: 1.17-6.24, respectively). Also, these polymorphisms were associated with CYP metabolite levels in patients with ND.

CONCLUSIONS

ND is fairly common in acute ischemic stroke. Specific CYP gene SNPs are associated with CYP plasma metabolite levels, which may explain their associations with ND. Further studies are needed to validate our findings.

20-Hydroxyeicosatetraenoic Acid as a Predictor of Neurological Deterioration in Acute Minor Ischemic Stroke

BACKGROUND AND PURPOSE

The relationship between high plasma 20-hydroxyeicosatetraenoic acid (20-HETE) levels and neurological deterioration (ND) has not been investigated in patients with acute minor ischemic stroke.

METHOD

We conducted a prospective, multicenter observational study in patients with acute minor ischemic stroke. Plasma levels of 20-HETE were measured at admission in all patients. The primary end point of the study was ND within 10 days after admission. The degree of disability was assessed using modified Rankin scale at 3 months after admission.

RESULTS

A total of 322 patients were enrolled, of which 85 patients (26.4%) developed ND. Mean 20-HETE level was 1687±158 pmol/L. On multivariate analyses, high level (>1675 pmol/L) of 20-HETE was an independent predictor of ND (third and fourth quartiles). Neurological deterioration was associated with a higher risk of poor outcome (modified Rankin scale scores 3-6) at 3 months.

CONCLUSIONS

ND is fairly common in acute minor ischemic stroke and is associated with poor prognosis. Elevated plasma level of 20-HETE may be a predictor for ND in acute minor ischemic stroke.

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.

Interactions Among CYP2C8, EPHX2, and CYP4A11 Variants and CYP Plasma Metabolite Levels in Ischemic Stroke

Aim: To better understand the relationship between the interactions among rs17110453, rs751141, and rs9333025 variants and plasma levels of cytochrome P450 (CYP) metabolites, i.e., 20-hydroxyeicosatetraenoic acid (20-HETE), epoxyeicosatrienoic acids (EETs), and dihydroxyeicosatrienoic acids (DiHETEs) in ischemia stroke (IS).

Methods: We measured plasma CYP metabolite levels in 218 acute IS cases and 126 controls, and a subset of samples were assessed to further understand the association between relevant variants and IS risk in our previous study. We assessed the associations between variant interactions and levels of 20-HETE, EETs, and DiHETEs as well as the associations between levels of 20-HETE, EETs, and DiHETEs and IS risk after adjusting for other potential confounders. Furthermore, the association between variant interactions and IS risk after adjusting for other covariates, including CYP metabolites levels, was evaluated.

Results: The interactions among variants rs17110453, rs751141, and rs9333025 were significantly associated with high 20-HETE, high DiHETEs, and low EETs after adjusting for the status of diabetes mellitus and hypertension. High 20-HETE, high DiHETEs, and low EETs were independent risk factors for IS after adjusting for hypertension, diabetes mellitus, and the interactions among rs17110453, rs751141, and rs9333025. Furthermore, the interactions among rs17110453, rs751141, and rs9333025 were significantly associated with a higher risk of IS after adjusting for CYP metabolites (OR= 2.02, 95% CI: 1.28–5.27, P = 0.007).

Conclusion: The association between the interactions among rs17110453, rs751141, and rs9333025 and IS risk in Chinese population may be partly but not exclusively mediated by plasma levels of 20-HETE, EETs, and DHETs. Further well-designed studies are warranted to replicate this finding.