Association between cytochrome P450 promoter polymorphisms and ischemic stroke

A Genome-Wide Analysis of a Sudden Cardiac Death Cohort: Identifying Novel Target Variants in the Era of Molecular Autopsy

Sudden cardiac death (SCD) is an unexpected natural death due to cardiac causes, usually happening within one hour of symptom manifestation or in individuals in good health up to 24 h before the event. Genomic screening has been increasingly applied as a useful approach to detecting the genetic variants that potentially contribute to SCD and helping the evaluation of SCD cases in the post-mortem setting. Our aim was to identify the genetic markers associated with SCD, which might enable its target screening and prevention. In this scope, a case-control analysis through the post-mortem genome-wide screening of 30 autopsy cases was performed. We identified a high number of novel genetic variants associated with SCD, of which 25 polymorphisms were consistent with a previous link to cardiovascular diseases. We ascertained that many genes have been already linked to cardiovascular system functioning and diseases and that the metabolisms most implicated in SCD are the lipid, cholesterol, arachidonic acid, and drug metabolisms, suggesting their roles as potential risk factors. Overall, the genetic variants pinpointed herein might be useful markers of SCD, but the novelty of these results requires further investigations.

Crude Polysaccharide Extracted From Moringa oleifera Leaves Prevents Obesity in Association With Modulating Gut Microbiota in High-Fat Diet-Fed Mice

Moringa oleifera is a commonly used plant with high nutritional and medicinal values. M. oleifera leaves are considered a new food resource in China. However, the biological activities of M. oleifera polysaccharides (MOP) in regulating gut microbiota and alleviating obesity remain obscure. In the present study, we prepared the MOP and evaluated its effects on obesity and gut microbiota in high-fat diet (HFD)-induced C57BL/6J mice. The experimental mice were supplemented with a normal chow diet (NCD group), a high-fat diet (HFD group), and HFD along with MOP at a different dose of 100, 200, and 400 mg/kg/d, respectively. Physiological, histological, biochemical parameters, genes related to lipid metabolism, and gut microbiota composition were compared among five experimental groups. The results showed that MOP supplementation effectively prevented weight gain and lipid accumulation induced by HFD, ameliorated blood lipid levels and insulin resistance, alleviated the secretion of pro-inflammatory cytokines, and regulated the expression of genes related to lipid metabolism and bile acid metabolism. In addition, MOP positively reshaped the gut microbiota composition, significantly increasing the abundance of Bacteroides, norank_f_Ruminococcaceae, and Oscillibacter, while decreasing the relative abundance of Blautia, Alistipes, and Tyzzerella, which are closely associated with obesity. These results demonstrated that MOP supplementation has a protective effect against HFD-induced obesity in mice, which was associated with reshaping the gut microbiota. To the best of our knowledge, this is the first report on the potential of MOP to prevent obesity and modulating gut microbiota, which suggests that MOP can be used as a potential prebiotic.

The association of cytochrome 7A1 and ATP-binding cassette G8 genotypes with type 2 diabetes among Jordanian patients

OBJECTIVES

Increased cholesterol levels were found to be associated with diabetes mellitus type II (DM2). The cholesterol is metabolized by cytochrome 7A1 (CYP7A1) and transported in the intestine by ATP-binding cassette G8 (ABCG8). Genetic variants in CYP7A1 and ABCG8 genes can affect the cholesterol levels. The aim of this study is to compare the frequency of CYP7A1 rs3808607 and ABCG8 rs11887534 and rs4148217 genotypes between healthy and DM2 subjects from Jordanian population.

METHODS

A total of 117 DM2 patients and 100 healthy controls, of Jordanian Arabic origin, were genotyped for CYP7A1 rs3808607 and ABCG8 rs11887534 and rs4148217 genetic variants using polymerase chain reaction (PCR) followed by restriction fragment length polymorphism technique.

RESULTS

The study showed that homozygosity of rs3808607 (A-204C) genotype in CYP7A1 was significantly higher in DM2 patients (ANOVA, p<0.05) with an odd ratio of 2.66, but rs11887534 (G55C) and rs4148217 (C1199A) genetic polymorphisms in ABCG8 were found in comparable frequencies in both healthy and DM2 subjects.

CONCLUSIONS

The results of this study indicate that CYP7A1 rs3808607 genetic polymorphism is associated with DM2. Further clinical studies are required to confirm this finding among DM2 patients of Jordanian origin.

CYP3A4 and CYP11A1 variants are risk factors for ischemic stroke: a case control study

Background

This study aimed to investigate the roles of CYP3A4 and CYP11A1 variants in ischemic stroke (IS) susceptibility among the Han Chinese population.

Methods

Four hundred seventy-seven patients with IS and 493 healthy controls were enrolled. Seven single-nucleotide polymorphisms (SNPs) of CYP3A4 and CYP11A1 were genotyped by Agena MassARRAY. Odds ratio (OR) and 95% confidence intervals (CI) were calculated by logistic regression adjusted for age and gender.

Results

We found that CYP3A4 rs3735451 (OR = 0.81, p = 0.039) and rs4646440 (OR = 0.72, p = 0.021) polymorphisms decreased the risk of IS. CYP3A4 rs4646440 (OR = 0.74, p = 0.038) and CYP11A1 rs12912592 (OR = 1.58, p = 0.034) polymorphisms were correlated with IS risk in males. CYP3A4 rs3735451 (OR = 0.63, p = 0.031) and rs4646440 (OR = 0.57, p = 0.012) possibly weaken the IS susceptibility at age > 61 years. Besides, CYP3A4 rs4646437 (OR = 0.59, p = 0.029), CYP11A1 rs12912592 (OR = 1.84, p = 0.017) and rs28681535 (OR = 0.66, p = 0.038) were associated with IS risk at age ≤ 61 years. CYP11A1 rs28681535 TT genotype was higher high-density lipoprotein cholesterol level than the GT and GG genotype (p = 0.027).

Conclusions

Our findings indicated that rs3735451, rs4646440, rs4646437 in CYP3A4 and rs28681535 in CYP11A1 might be protective factors for IS, while CYP11A1 rs12912592 polymorphism be a risk factor for IS in Chinese Han population.

Genetics of platelet traits in ischaemic stroke: focus on mean platelet volume and platelet count

Purpose/Aim of the study: The aim of this review is to summarize the role of genetic variants affecting mean platelet volume (MPV) and platelet count (PLT) leading to higher platelet reactivity and in turn to thrombotic events like stroke and cardiovascular diseases.

MATERIALS AND METHODS

A search was conducted in PUBMED, MEDLINE, EMBASE, PROQUEST, Science Direct, Cochrane Library, and Google Scholar related to the studies focussing on genome-wide association studies (GWAS), whole exome sequencing (WES), whole genome sequencing (WGS), phenome-wide association studies (PheWAS) and multi-omic analysis that have been employed to identify the genetic variants influencing MPV and PLT.

RESULTS

Antiplatelet agents underscore the crucial role of platelets in the pathogenesis of stroke. Higher platelet reactivity in terms of mean platelet volume (MPV) and platelet count (PLT) contributes significantly to the interindividual variation in platelet reaction at the site of vessel wall injury. Some individuals encounter thrombotic events as platelets get occluded at the site of vessel wall injury whereas others heal the injury without occluding the circulation. Evidence suggests that MPV and PLT have a strong genetic component. High throughput techniques including genome-wide association studies (GWAS), whole exome sequencing (WES), whole genome sequencing (WGS), phenome-wide association studies (PheWAS) and multi-omic analysis have identified different genetic variants influencing MPV and PLT.

CONCLUSIONS

Identification of complex genetic cross talks affecting PLT and MPV might help to develop novel treatment strategies in treating neurovascular diseases like stroke.

Interactions Between Regulatory Variants in CYP7A1 (Cholesterol 7α-Hydroxylase) Promoter and Enhancer Regions Regulate CYP7A1 Expression

BACKGROUND

CYP7A1 (cholesterol 7α-hydroxylase) catalyzes the rate-limiting step in bile acid biosynthesis from cholesterol-a main pathway for cholesterol removal from the body. CYP7A1 single-nucleotide polymorphisms (SNPs) are associated with total cholesterol and LDL (low-density lipoprotein) levels, risk of cardiovascular diseases, and other phenotypes; however, results are inconsistent, and causative variants remain uncertain, except for a frequent promoter SNP (rs3808607).

METHODS

We used chromatin conformation capture (4C assay), chromatin immunoprecipitation qPCR assay in hepatocytes, and CRISPR (clustered regularly interspaced short palindromic repeats)-mediated genome editing in hepatocellular carcinoma cell line cells to identify regulatory regions for CYP7A1. We then screened for SNPs located in regulatory regions, testing effects on reporter gene assays and on hepatic CYP7A1 expression by measuring allelic mRNA expression imbalance.

RESULTS

4C assays showed several regions interacting with CYP7A1 promoter. CRISPR-mediated genome editing in hepatocellular carcinoma cell line cells revealed a novel CYP7A1 enhancer and a repressor region, located >10 kb downstream of the CYP7A1 promoter. SNP screening with an allelic mRNA expression imbalance in human livers and reporter gene assays identified a frequent functional SNP (rs9297994) located in the downstream CYP7A1 enhancer region. SNP rs9297994 is in high linkage disequilibrium with promoter SNP rs3808607 but has opposite effects on CYP7A1 mRNA expression. Their combined effects using a 2-SNP model robustly associate with hepatic CYP7A1 mRNA expression, ranging >2 orders of magnitude. Moreover, only the 2-SNP model, but not each SNP alone, is significantly associated with LDL levels, risk of coronary artery disease, statin response, and diabetes mellitus in several clinical cohorts, including CATHGEN (Catheterization Genetics) and Framingham.

CONCLUSIONS

Two interacting regulatory SNPs modulate CYP7A1 expression and are associated with risk of coronary artery disease and diabetes mellitus.

Genetics and Genomics of Acute Neurologic Disorders

Neurologic diseases and injuries are complex and multifactorial, making risk prediction, targeted treatment modalities, and outcome prognostication difficult and elusive. Genetics and genomics have affected clinical practice in many aspects in medicine, particularly cancer treatment. Advancements in knowledge of genetic and genomic variability in neurologic disease and injury are growing rapidly. Although these data are not yet ready for use in clinical practice, research continues to progress and elucidate information that eventually will provide answers to complex neurologic questions and serve as a platform to provide individualized care plans aimed at improving outcomes. This article provides a focused review of relevant literature on genetics, genomics, and common complex neurologic disease and injury likely to be seen in the acute care setting.

CYP2E1 Gene Polymorphisms Related to the Formation of Coronary Artery Lesions in Kawasaki Disease

BACKGROUND

Kawasaki disease (KD) is an acute febrile systemic vasculitis that disturbs coronary arteries. Patients' risks of adverse cardiovascular events and subclinical atherosclerosis have been found to significantly increase with polymorphisms of the human cytochrome P450. This current study aims to research the possible relationship between cytochrome P450, family 2, subfamily E and polypeptide 1 (CYP2E1) polymorphisms with KD.

METHODS

We selected 6 tag single-nucleotide polymorphisms (SNPs) of the CYP2E1 gene for TaqMan allelic discrimination assay in 340 KD patients and performed analysis on the clinical phenotypes and coronary artery lesions (CALs). CAL associations of tag SNPs were adjusted for age and gender in the logistic regression.

RESULTS

The KD patients with a CC genotype of rs915906 demonstrated a greater proportion of CAL formation (P = 0.009). Furthermore, the GG genotype frequencies of rs2070676 showed a significantly greater risk for CAL formation in KD patients (P = 0.007). However, the SNPs of the CYP2E1 gene did not influence CAL formation in the participating KD patients either with or without high-dose acetylsalicylic acid. Using the expression quantitative trait locus analyses, we found that the SNPs associated with CAL formation in KD also affected CYP2E1 expression in certain cell types.

CONCLUSION

This study is the first to find that the risk of CAL formation is related to CYP2E1 gene polymorphisms in KD patients.

Lack of an association between CYP11B2 C-344T gene polymorphism and ischemic stroke: a meta-analysis of 7,710 subjects

Background

The association between aldosterone synthase (CYP11B2) C-344T gene polymorphism and ischemic stroke remains controversial and ambiguous. To better explain the association between CYP11B2 polymorphism and ischemic stroke risk, a meta-analysis was performed.

Methods

Based on comprehensive searches of Medline, Embase, Web of Science, CNKI and CBM databases, we identified and abstracted outcome data from all articles to evaluate the association between CYP11B2 polymorphism and ischemic stroke. The pooled odds ratios (ORs) with 95% confidence intervals (CIs) were performed in all genetic models. Fixed or random effects model was separately used depending on the heterogeneity between studies. Publication bias was tested by Begg's funnel plot and Egger's regression test.

Results

A total of 12 studies including 3,620 ischemic stroke cases and 4,090 controls were identified. There was no statistical evidence of association between CYP11B2 C-344T polymorphism and ischemic stroke in all genetic models (allelic model: OR = 1.19, 95% CI = 0.95–1.49; additive model: OR = 1.43, 95% CI = 0.91–2.27; dominant model: OR = 1.30, 95% CI = 0.89–1.89; and recessive model: OR = 1.24, 95% CI = 0.96–1.60). On subgroup analysis by ethnicity, similarly results were found in both Asians and non-Asians. For Asians, the combined ORs and 95% CIs were (allelic model: OR = 1.07, 95% CI = 0.87–1.32; additive model: OR = 1.15, 95% CI = 0.77–1.71; dominant model: OR = 1.13, 95% CI = 0.92–1.38; and recessive model: OR = 1.09, 95% CI = 0.84–1.40). For none-Asians, the combined ORs and 95% CIs were (allelic model: OR = 1.58, 95% CI = 0.90–2.76; additive model: OR = 2.37, 95% CI = 0.79–7.05; dominant model: OR = 1.79, 95% CI = 0.77–4.19; and recessive model: OR = 1.80, 95% CI = 0.96–3.36).

Conclusion

The present meta-analysis suggested that CYP11B2 C-344T polymorphism was unlikely contribute to ischemic stroke susceptibility.

The CYP11B2 -344C/T variant is associated with ischemic stroke risk: An updated meta-analysis

INTRODUCTION

The CYP11B2 gene has been suggested to play an important role in the pathogenesis of ischemic stroke. However, the results have been inconsistent. In this study, we performed a meta-analysis to clarify the association of the CYP11B2 -344C/T variant with ischemic stroke.

METHODS

Published literature from PubMed and Embase were retrieved. Pooled odds ratio with 95% confidence interval was calculated using a fixed- or random-effects model. A total of seven studies (2765 stroke cases and 3118 controls) for the CYP11B2 -344C/T variant were included in the meta-analysis.

RESULTS

The meta-analysis indicated that the CYP11B2 -344C/T variant was significantly associated with ischemic stroke under a homogeneous co-dominant model (TT vs. CC: odds ratio=2.04, 95% confidence interval=1.21-3.45), dominant model (TT+TC vs. CC: odds ratio=1.67, 95% confidence interval=1.09-2.57) and recessive model (TT vs. TC+CC: odds ratio=1.56, 95% confidence interval=1.18-2.05) but not under a heterogeneous co-dominant model (TC vs. CC: odds ratio=1.43, 95% confidence interval=0.98-2.07). Further subgroup analysis showed that the CYP11B2 -344C/T variant was significantly associated with ischemic stroke in East Asian and South Asian populations, but not in a Caucasian population.

CONCLUSION

The present meta-analysis supported the positive association of the CYP11B2 -344C/T variant with ischemic stroke. Further large-scale studies considering gene-gene/gene-environment interactions should be conducted to investigate the association.

Mechanically assisted intra-arterial thrombolysis in acute cerebral infarction

The aim of this study was to assess the clinical efficacy and safety of mechanically assisted thrombolysis in the treatment of acute cerebral infarction. Mechanically assisted intra-arterial urokinase thrombolysis was conducted on 28 patients with acute cerebral infarction with a disease onset time of 90–450 min. The maximum level of urokinase was 1,150,000 units. Thrombus disruption with a microwire, retrieval with a microcatheter and stent-assisted revascularization were performed. The recanalization rate, bleeding complications and modified Rankin scale (mRS) score were observed within 3 months of surgery. Our results showed that mechanically assisted thrombolysis was successfully conducted on 23 patients, with a recanalization rate of 82.1% (23/28), average recanalization time of 65.22 min and mRS score ≤3.5. Five cases of recanalization were invalid, including 2 cases of mortality, 1 case with an mRS score of 4 and 2 cases with an mRS score ≤3. In the recanalization group, the mechanically assisted thrombolysis did not increase the number of bleeding complications. Our study demonstrated that the safety of mechanically assisted thrombolysis for the treatment of acute cerebral infarction is equivalent to that of simple intra-arterial thrombolysis, but that the former has a higher efficiency. Mechanically assisted thrombolysis is able to reduce the urokinase dosage and recanalization time, and increase the recanalization rate.

Aldosterone synthase gene (CYP11B2) -344C/T polymorphism contributes to the risk of recurrent cerebral ischemia

BACKGROUND

Accumulating evidence suggests that CYP11B2 rs1799998 (-344C/T) polymorphism is independently associated with an increased risk of stroke. Our aim was to determine whether -344C/T also predisposes to recurrent cerebral ischemia following in patients with symptomatic intracranial atherosclerosis disease (ICAD).

METHODS

Genotypes of the CYP11B2 -344C/T polymorphism were determined by polymerase chain reaction-restriction fragment length polymorphism. A total of 208 ICAD patients were enrolled and underwent a long-term clinical follow-up to detect the recurrent cerebral ischemia.

RESULTS

During a median follow-up time of 35 months, 40 recurrent strokes (19.2%) were documented. Kaplan-Meier and multivariable Cox regression analyses adjusted for age, gender, and other cardiovascular risk factors identified that the presence of the TT genotype within the CYP11B2 -344C/T polymorphism was associated with an increased risk of 1.98-fold for recurrent cerebral ischemia (the hazard ratio 1.98, 95% confidence interval 1.16-3.41; p=0.01).

CONCLUSIONS

Our findings suggest that the -344C/T polymorphism of the CYP11B2 gene confers an increased risk of recurrent cerebral ischemia.