Clinical Relevance of MTHFR, eNOS, ACE, and ApoE Gene Polymorphisms and Serum Vitamin Profile among Malay Patients with Ischemic Stroke

MTHFR C677T, hyperhomocysteinemia, and their interactions with traditional risk factors in early neurological deterioration in Chinese patients with ischemic stroke

Objective

This study aimed to investigate the relationship between methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and early neurological deterioration (END) in patients with acute ischemic stroke (AIS) and any possible interactions between specific MTHFR alleles and traditional risk factors among a Han Chinese cohort.

Methods

434 AIS patients were consecutively recruited between January 2017 and June 2019, including 129 END and 305 non-END cases. A candidate gene association study design was used to analyze the association between MTHFR gene polymorphism and END risk. The polymerase chain reaction-restriction fragment length polymorphism (RFLP) method was employed to genotype the MTHFR C677T polymorphism. The interactional analyses were performed using the multifactor dimensionality reduction test.

Results

Hyperglycemia (odds ratio [OR]: 2.410, 95 % confidence interval [CI]: 1.436-4.046, p = 0.001), neurological function impairment (NIHSS score >5) (OR: 2.158, 95%CI: 1.337-3.484, p = 0.002) on admission, and hyperhomocysteinemia (HHcy) (OR: 2.570, 95%CI: 1.229-5.376, p = 0.012) were independently associated with END. The TT genotype (OR: 1.710, 95%CI: 1.021-2.863, p = 0.043) and T allele (OR: 1.710, 95%CI: 1.021-2.863, p = 0.043) of this C677T polymorphism were associated with susceptibility to END, and the TT genotype was more common in the subjects with HHcy (OR: 2.525, 95%CI: 1.111-5.739, P = 0.023). In addition, we also found interactions for END risk between the C677T polymorphism and traditional risk factors for END, including: hyperglycemia on admission, drinking, and moderate to severe neurological deficits (OR 1.237, 95 % CI 0.227-6.734), although the results were not statistically significant (p = 0.806).

Conclusions

Our results show a possible association between MTHFR C677T polymorphism and gene-environment interactions with END susceptibility in a Han Chinese cohort.

A Proactive Intervention Study in Metabolic Syndrome High-Risk Populations Using Phenome-Based Actionable P4 Medicine Strategy

The integration of predictive, preventive, personalized, and participatory (P4) healthcare advocates proactive intervention, including dietary supplements and lifestyle interventions for chronic disease. Personal profiles include deep phenotypic data and genetic information, which are associated with chronic diseases, can guide proactive intervention. However, little is known about how to design an appropriate intervention mode to precisely intervene with personalized phenome-based data. Here, we report the results of a 3-month study on 350 individuals with metabolic syndrome high-risk that we named the Pioneer 350 Wellness project (P350). We examined: (1) longitudinal (two times) phenotypes covering blood lipids, blood glucose, homocysteine (HCY), and vitamin D3 (VD3), and (2) polymorphism of genes related to folic acid metabolism. Based on personalized data and questionnaires including demographics, diet and exercise habits information, coaches identified 'actionable possibilities', which combined exercise, diet, and dietary supplements. After a 3-month proactive intervention, two-thirds of the phenotypic markers were significantly improved in the P350 cohort. Specifically, we found that dietary supplements and lifestyle interventions have different effects on phenotypic improvement. For example, dietary supplements can result in a rapid recovery of abnormal HCY and VD3 levels, while lifestyle interventions are more suitable for those with high body mass index (BMI), but almost do not help the recovery of HCY. Furthermore, although people who implemented only one of the exercise or diet interventions also benefited, the effect was not as good as the combined exercise and diet interventions. In a subgroup of 226 people, we examined the association between the polymorphism of genes related to folic acid metabolism and the benefits of folate supplementation to restore a normal HCY level. We found people with folic acid metabolism deficiency genes are more likely to benefit from folate supplementation to restore a normal HCY level. Overall, these results suggest: (1) phenome-based data can guide the formulation of more precise and comprehensive interventions, and (2) genetic polymorphism impacts clinical responses to interventions. Notably, we provide a proactive intervention example that is operable in daily life, allowing people with different phenome-based data to design the appropriate intervention protocol including dietary supplements and lifestyle interventions.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43657-023-00115-z.

Association of CELSR2, APOB100, ABCG5/8, LDLR, and APOE polymorphisms and their genetic risks with lipids among the Thai subjects

Background

Hypercholesterolemia is a common cardiovascular risk factor. The aim of this study was to investigate the association of CELSR2 (rs629301), APOB100 (rs1367117), ABCG5/8 (rs6544713), LDLR (rs6511720), and APOE (rs429358, rs7412) polymorphisms, and their genetic risk scores with lipids among Thai subjects.

Methods

A total of 459 study subjects (184 males, and 275 females) were enrolled. Blood pressure, serum lipids, and fasting blood sugar were measured. CELSR2 (rs629301), APOB100 (rs1367117), ABCG5/8 (rs6544713), and LDLR (rs6511720) polymorphisms were analyzed using PCR-HRM. APOE (rs429358, rs7412) polymorphism was analyzed using PCR-RFLP.

Results

Total cholesterol (TC) levels were significantly higher in APOB100 AA genotype compared with GG, or AA + AG genotypes in total subjects. In addition, significantly higher concentrations of TC and low density lipoprotein cholesterol (LDL-C) were observed in APOE4 carriers compared to APOE2 carriers in total subjects, males, and females. The significantly higher concentrations of TC were observed in APOE4 carriers compared to APOE3 carriers in females. Moreover, the concentrations of TC, and LDL-C were significantly increased with genetic risk scores of APOB100, and APOE polymorphisms in total subjects, and females. There was no association between CELSR2 (rs629301), ABCG5/8 (rs6544713), and LDLR (rs6511720) polymorphisms and serum lipids.

Conclusion

APOB100 (rs1367117), and APOE (rs429358, rs7412) but not CELSR2 (rs629301), ABCG5/8 (rs6544713), and LDLR (rs6511720) polymorphisms were associated with serum lipids. The cumulative risk alleles of APOB100 (rs1367117), and APOE (rs429358, rs7412) polymorphisms could enhance the elevated concentrations of TC, and LDL-C, and they may be used to predict severity of hypercholesterolemia among Thai subjects.

Association of methylenetetrahydrofolate reductase (MTHFR) rs1801133 (677C>T) gene polymorphism with ischemic stroke risk in different populations: An updated meta-analysis

Background: Recently, increasing evidence has implicated methylenetetrahydrofolate reductase (MTHFR) gene mutation as a risk factor for ischemic stroke (IS) in the general population. However, studies have been inconclusive and lack evidence on specific populations. We aim to determine whether the rs1801133 (NC_000001.11 (MTHFR):g. 677C>T (p.Ala222Val) variant, we termed as MTHFR rs1801133 (677 C>T), is linked to an increased risk of IS in different age groups and ancestry groups. Methods: The literature relevant to our study was found by searching the PubMed, Cochrane Library, Web of Science, EMBASE, and CNKI databases. A random effect model analysis was used to calculate the pooled odds ratio (OR) and 95% confidence interval (CI) to evaluate any possible association. We conducted a subgroup analysis based on the age and ancestry groups of the included populations. Results: As of March 2022, 1,925 citations had been identified in electronic databases, of which 96 studies involving 34,814 subjects met our eligibility criteria. A strong link was found between IS and the MTHFR gene rs1801133 (677C>T) polymorphism in all genetic models [dominant genetic model (OR = 1.47; 95%CI = 1.33-1.61; p < 0.001), recessive genetic model (OR = 1.52; 95%CI = 1.36-1.71; p < 0.001), heterozygous model (OR = 1.36; 95%CI = 1.24-1.48; p < 0.001), homozygous model (OR = 1.82; 95%CI = 1.58-2.11; p < 0.001), and T allelic genetic model (OR = 1.37; 95%CI = 1.27-1.48; p < 0.001)]. Further subgroup analyses indicated that the MTHFR rs1801133 (677C>T) variant may increase the risk of IS in Asian, Hispanic, or Latin population, middle-aged, and elderly populations (p < 0.001). Conclusion: Our results implied that mutation of the T allele of MTHFR rs1801133 (677C>T) could be a risk factor for IS. A significant association was found among Asian, Hispanic, or Latin population, middle-aged, and elderly people.

Apolipoprotein E ε4 Polymorphism as a Risk Factor for Ischemic Stroke: A Systematic Review and Meta-Analysis

Introduction

Rising studies indicate that the apolipoprotein E (APOE) gene is related to the susceptibility of ischemic stroke (IS). However, certain consensus is limited by the lack of a large sample size of researches. This meta-analysis was performed to explore the potential association between the APOE gene and IS.

Methods

To identify relevant case control studies in English publications by October 2020, we searched PubMed, Embase, Web of Science, and the Cochrane Library. Pooled odds ratios (ORs) with fixed- or random-effect models and corresponding 95% confidence intervals (CIs) were calculated to analyze potential associations.

Results

A total of 55 researches from 32 countries containing 12207 IS cases and 27742 controls were included. The association between APOE gene ε4 mutation and IS was confirmed (ε4 vs. ε3 allele: pooled OR = 1.374, 95% CI, 1.214-1.556; ε2/ε4 vs. ε3/ε3: pooled OR = 1.233, 95% CI, 1.056-1.440; ε3/ε4 vs. ε3/ε3: pooled OR = 1.340, 95% CI, 1.165-1.542; ε4/ε4 vs. ε3/ε3: pooled OR = 1.833, 95% CI, 1.542-2.179; and APOE ε4 carriers vs. non-ε4 carriers: pooled OR = 1.377; 95% CI, 1.203-1.576). Interestingly, APOE ε4 mutation showed a dose-response correlation with IS risk (ε4/ε4 vs. ε2/ε4: pooled OR = 1.625; 95% CI, 1.281-2.060; ε4/ε4 vs. ε3/ε4: pooled OR = 1.301; 95% CI, 1.077-1.571). Similar conclusions were drawn in the small artery disease (SAD) subtype, but not in large artery atherosclerosis (LAA) or in cardioaortic embolism (CE), by subgroup analysis.

Conclusions

These observations reveal that specific APOE ε4 mutation was significantly associated with the risk of IS in a dose-dependent manner, while APOE ε4 mutation was related to SAD subtype onset without a cumulative effect.

MTHFR A1298C gene polymorphism on stroke risk: an updated meta-analysis

Background

Previous studies have shown the effect of MTHFR A1298C gene polymorphism on stroke risk. But the results of published studies remained inconclusive and controversial. So we conducted a meta-analysis to accurately estimate the potential association between MTHFR A1298C gene polymorphism and stroke susceptibility.

Methods

A systematic literature search on Embase, Pubmed, Web of Science, Cochrane Library, China National Knowledge Infrastructure (CNKI) and WanFang electronic database identified 40 articles including 5725 cases and 8655 controls. Strength of association was evaluated by pooled odds ratio (OR), 95% confidence interval (CI) and p value. Funnel plots and Begger’s regression test were applied for testing the publication bias. Statistical analysis of all data was performed by Stata 12.0.

Results

The meta-analysis results indicated a significant relationship between MTHFR gene A1298C polymorphisms and stoke risk under the C allelic genetic model (OR = 1.19, 95%CI = 1.07–1.32, p = 0.001), dominant genetic model (OR = 1.19, 95%CI = 1.06–1.33, p = 0.004) and recessive genetic model (OR = 1.43, 95%CI =1.15–1.77, p = 0.001). In subgroup analysis, we discovered obvious correlation in three genetic model of Asian, stroke type, adult by ethnicity, population, stroke type, source of control and case size. Additionally, in studies of control from hospital and case size equal 100, obvious correlation was also found in the three genetic model.

Conclusions

Our meta-analysis results indicated that there was evidence to support the correlation between MTHFR A1298C polymorphism and stroke susceptibility, especially in adults and ischemic stroke.

SLC17A3 rs9379800 and Ischemic Stroke Susceptibility at the Northern Region of Malaysia

OBJECTIVES

The relationships of Paired Like Homeodomain 2 (PITX2), Ninjurin 2 (NINJ2), TWIST-Related Protein 1 (TWIST1), Ras Interacting Protein 1 (Rasip1), Solute Carrier Family 17 Member 3 (SLC17A3), Methylmalonyl Co-A Mutase (MUT) and Fer3 Like BHLH Transcription Factor (FERD3L) polymorphisms and gene expression with ischemic stroke have yet to be determined in Malaysia. Hence, this study aimed to explore the associations of single nucleotide polymorphisms (SNPs) and gene expression with ischemic stroke risk among population who resided at the Northern region of Malaysia.

MATERIALS AND METHODS

Study subjects including 216 ischemic stroke patients and 203 healthy controls were recruited upon obtaining ethical clearance. SNP genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism assays. Gene expression levels were quantified by real-time polymerase chain reaction assays. Statistical and genetic analyses were conducted with SPSS version 22.2, PLINK version 1.07 and multifactor dimensionality reduction software.

RESULTS

Study subjects with G allele, CG or GG genotypes of SLC17A3 rs9379800 demonstrated increased risk of ischemic stroke with the odds ratios ranging from 1.76-fold to 3.14-fold (p<0.05). When stratified study subjects according to the ethnicity, SLC17A3 rs9379800 G allele and CG genotype contributed to 2.14- and 2.96-fold of ischemic stroke risk among Malay population significantly, in the multivariate analysis (p<0.05). However, no significant associations were observed for PITX2, NINJ2, TWIST1, Rasip1, and MUT polymorphisms with ischemic stroke risk in the multivariate analysis for the pooled cases and controls as well as when stratified them according to the ethnicity. Lower mRNA expression levels of Rasip1, SLC17A3, MUT and FERD3L were observed among cases (p<0.05). After FDR adjustment, the mRNA level of SLC17A3 remained significantly associated with ischemic stroke among Malay population (q=0.034).

CONCLUSION

In conclusion, this study suggests that SLC17A3 rs9379800 polymorphism and its gene expression contribute to significant ischemic stroke risk among Malaysian population, particularly the Malay who resided at the Northern Region of the country. Our findings can provide useful information for the future diagnosis, management and treatment of ischemic stroke patients.

MiR-10a, 27a, 34b/c, and 300 Polymorphisms are Associated with Ischemic Stroke Susceptibility and Post-Stroke Mortality

A recent study of the ischemic stroke described the roles played by miRNAs in the downregulation of specific cell-cycle gene expression and it is thought to require the development of biomarkers for the prognostic of ischemic stroke. Here, we hypothesized that four miRNA polymorphisms (miR-10a, miR-27a, miR-34b/c, and miR-300) may affect stroke susceptibility and mortality. Blood samples were collected from 530 patients and 403 controls. Genetic polymorphisms were detected by polymerase chain reaction (PCR)-restriction fragment length polymorphism analysis and real-time PCR. We found that the miR-300 rs12894467 TC genotype and the dominant model (AOR: 2.069, p-value: 0.017; AOR: 1.931, p-value: 0.027) were significantly associated with an increased risk for the ischemic stroke subtype. In Cox proportional hazard regression models, the miR-10a rs3809783 A>T and miR-34b/c rs4938723 T>C polymorphisms were associated with the mortality rates among ischemic stroke patients. We found that a miR-300 polymorphism was associated with increased ischemic stroke susceptibility among the Korean population. Additionally, polymorphisms in miR-10a and miR-34b/c were associated with the increased or decreased mortality of ischemic stroke patients. This study marks the first report of an association between ischemic stroke and miRNA polymorphisms (miR-10aA>T, miR-27aT>C, miR-34b/cT>C, and miR-300T>C) in the Korean population.

CD271+ stem cell treatment of patients with chronic stroke: : A retrospective case series report

Patients with chronic stroke have currently little hope for motor improvement towards regaining independent activities of daily living; stem cell treatments offer a new treatment option and needs to be developed. Patients with chronic stroke (more than 3 months prior to stem cell treatment, mean 21.2 months post-stroke) were treated with CD271+ stem cells, 7 patients received autologous and 1 allogeneic cells from first degree relative; administration was intravenous in 1 and intrathecal in 7 patients. Each patient received a single treatment consisting of 2-5x106 cells/kg and they were followed up for up to 12 months. There were significant improvements in expressive aphasia (2/3 patients) spasticity (5/5, of which 2 were transient), and small improvements in motor function (2/8 patients). Although motor improvements were minor in our chronic stroke patients, improvements in aphasia and spasticity were significant and in the context of good safety we are advocating further administration and clinical studies of CD271+ stem cells not only in chronic stroke patients, but also for spastic paresis/plegia; a different, yet unexplored application is pulmonary emphysema.

Research of stroke combined hyperlipidemia-induced erectile dysfunction in rat model

Objective: The study was aimed to evaluate the influences of erectile dysfunction (ED) in a rat model of stroke combined with hyperlipidemia (HLP). Methods: Male Sprague-Dawley rats were divided into control and hyperlipidemia (HLP) groups. HLP model was constructed by feeding with high-fat and cholesterol diets. Serum levels of total cholesterol (TC), low density lipoprotein (LDL), high density lipoprotein (HDL), triglyceride (TG), and non-HDL were identified to check the model was success. Stroke model was established by FeCl₃. ICP/MAP value was detected to evaluate the erectile function of rats. Serum level of lipoproteins and the expressions of endothelial nitric oxide synthase (eNOS), vascular endothelial growth factor (VEGF) were detected by ELISA. Hematoxylin-eosin (HE) staining of corpus cavernosum and measurement of penis length were utilized to assessment erectile function. Western blot was used. Results: TC, TG, LDL, and non-HDL-C in serum were up-regulated, while HDL level was attenuated. After treatment, the serum lipid level recovered. From the ICP/MAP values, the erectile function of both two treatment groups recovered. The expression of PDE5A was up-regulated, while the levels of eNOS and cGMP were suppressed after surgery. The length of penis was decreased, and corpus cavernosum was damaged following HLP and stroke. However, the erectile function was recovered after treatment. Conclusion: Stroke combined HLP caused ED through NO-cGMP-PDE5 pathway.

Associations for BCO2, PCSK9, and TR1B1 Polymorphism and Lifestyle Factors with Ischemic Stroke: A Nested Case-Control Study

PURPOSE

To investigate associations for polymorphisms in β-carotene 9',10'-oxygenase (BCO2, rs10431036 and rs11214109), proprotein convertase subtilisin kexin type 9 (PCSK9, rs11583680), and tribbles pseudokinase 1 (TRIB1, rs17321515 and rs2954029), as well as lifestyle factors, with ischemic stroke (IS).

MATERIALS AND METHODS

This nested case-control study included 161 patients with IS and 483 matched control individuals. We collected medical reports, lifestyle details, and blood samples from individuals and used the PCR-ligase detection reaction method to genotype single nucleotide polymorphisms (SNPs).

RESULTS

The GA+AA genotype of rs10431036 (p<0.001) and rs17321515 (p=0.003), the CT+TT genotype of rs11214109 (p=0.005), and the TA+AA genotype of rs2954029 (p=0.006) in dominant models increased the risk of IS. In additive models, the GG genotype of rs17321515 (p=0.005) and the TT genotype of rs2954029 (p=0.008) increased the risk of IS. Adequate intake of fruits/vegetables reduced the risk of IS (p=0.005). Although there was no interaction between genes and fruits/vegetables, people with inadequate intake of fruits/vegetables who carried a risk genotype had a higher risk of IS than those only having inadequate fruits/vegetables intake or those only carrying a risk genotype. Also, the haplotypes AC, AT, and GT (comprising rs10431036 and rs11214109) and GT (comprising rs2954029 and rs17321515) were found to be associated with an increased risk of IS (p<0.05).

CONCLUSION

Polymorphisms in BCO2 and TRIB1 and fruits/vegetables intake were associated with IS. These results provide the theoretical basis for gene screening to prevent chronic cerebrovascular diseases.

Association between interleukin-18 (137G/C and 607C/A) gene polymorphisms and risk of ischemic stroke: a meta-analysis

Over the years, numerous researchers have explored the relationship between ischemic stroke (IS) and interleukin-18 (IL-18) gene polymorphisms. However, those studies reported conflicting and ambiguous results. The effects of IL-18 (137G/C and 607C/A) genetic variants on IS were investigated in this article. We performed a systematic search that was comprehensively executed in online databases for studies published up to 30 April 2018. Calculation of pooled odds ratios (ORs) and 95% confidence intervals was applied to assess the intensity of correlation using Stata.12.0. The overall outcome showed that 137G allele increased the risk of IS under the homozygous model (OR=1.36, P=0.027). Nevertheless, on the basis of ethnicity for the subgroup analysis (Asian and Egyptian), it was disclosed that the association was only found in the Egyptian population under the allelic model (OR=2.72, P=0.001) and recessive model (OR=5.04, P=0.000). In the overall analysis, 607C allele increased the risk of IS under all hereditary models (C vs. A: OR=1.26, P=0.002; CC vs. AA: OR=1.67, P=0.002; CA vs. AA: OR=1.30, P=0.001; CC+CA vs. AA: OR=1.41, P=0.000; CC vs. AA+CA: OR=1.48, P=0.000); a similar trend was observed in the Asian population. However, 607C allele was linked to decreased IS risk in the Egyptian population under all genetic models except the heterozygous model (C vs. A: OR=0.48, P=0.006; CC vs. AA: OR=0.19, P=0.007; CA vs. AA: OR=0.47, P=0.078; CC+CA vs. AA: OR=0.39, P=0.020; CC vs. AA+CA:OR=0.30, P=0.030). Although two polymorphisms were associated with IS, the association varied significantly in different countries. Large epidemiological studies will be required to verify these findings in the future.

Metabolomics and Lipidomics of Ischemic Stroke

Ischemic stroke is a sudden loss of brain function due to the reduction of blood flow. Brain tissues cease to function with subsequent activation of the ischemic cascade. Metabolomics and lipidomics are modern disciplines that characterize the metabolites and lipid components of a biological system, respectively. Because the pathogenesis of ischemic stroke is heterogeneous and multifactorial, it is crucial to establish comprehensive metabolomic and lipidomic approaches to elucidate these alterations in this disease. Fortunately, metabolomic and lipidomic studies have the distinct advantages of identifying tissue/mechanism-specific biomarkers, predicting treatment and clinical outcome, and improving our understanding of the pathophysiologic basis of disease states. Therefore, recent applications of these analytical approaches in the early diagnosis of ischemic stroke were discussed. In addition, the emerging roles of metabolomics and lipidomics on ischemic stroke were summarized, in order to gain new insights into the mechanisms underlying ischemic stroke and in the search for novel metabolite biomarkers and their related pathways.

Interplay between 3'-UTR polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene and the risk of ischemic stroke

Stroke incidence is a multifactorial disease and especially hyperhomocysteinemia is associated with a higher risk of stroke. Previous studies have reported a folate metabolism disorder associated with the MTHFR gene. We investigated four single nucleotide polymorphisms in the MTHFR 3'-UTR [2572 C > A (rs4846049), 4869 C > G (rs1537514), 5488 C > T (rs3737967), and 6685 T > C (rs4846048)] to elucidate associations between ischemic stroke prevalence and prognosis. We examined 511 consecutive patients with ischemic stroke. Additionally, we selected 411 sex-/age-matched control subjects from patients presenting at our hospitals during the same period. The MTHFR 2572 C > A and 6685 T > C were significantly associated with ischemic stroke prevalence in the cardioembolism subgroup (MTHFR 2572CC vs. CA + AA: AOR, 2.145; 95% CI, 1.203-3.827; P = 0.010; MTHFR 6685TT vs. CC: AOR, 10.146; 95% CI, 1.297-79.336; P = 0.027). The gene-environment combined effect was significant, with MTHFR 2572CA + AA and folate levels ≤3.45 ng/mL correlating with ischemic stroke incidence. In addition, the total homocysteine (tHcy) levels in subjects with MTHFR 2572AA were elevated compared to tHcy levels in subjects with MTHFR 2572CC. Therefore, we suggest that MTHFR 2572 C > A and 6685 T > C are associated with ischemic stroke pathogenesis. The combined effects of the MTHFR 3'-UTR polymorphisms and tHcy/folate levels may contribute to stroke prevalence.

The impact of APOA5, APOB, APOC3 and ABCA1 gene polymorphisms on ischemic stroke: Evidence from a meta-analysis

BACKGROUND AND AIMS

Genetic studies have been reported on the association between APOA5, APOB, APOC3 and ABCA1 gene polymorphisms and ischemic stroke, but results remain controversial. Hence, this meta-analysis aimed to infer the causal relationships of APOA5 (rs662799, rs3135506), APOB (rs693, rs1042031, rs1801701), APOC3 (rs4520, rs5128, rs2854116, rs2854117) and ABCA1 rs2230806 with ischemic stroke risk.

METHODS

A systematic review was performed for all the articles retrieved from multiple databases, up until March 2017. Data were extracted from all eligible studies, and meta-analysis was carried out using RevMan 5.3 and R package 3.2.1. The strength of association between each studied polymorphism and ischemic stroke risk was measured as odds ratios (ORs) and 95% confidence intervals (CIs), under fixed- and random-effect models.

RESULTS

A total of 79 studies reporting on the association between the studied polymorphisms and ischemic stroke risk were identified. The pooled data indicated that all genetic models of APOA5 rs662799 (ORs = 1.23-1.43), allelic and over-dominant models of APOA5 rs3135506 (ORs = 1.77-1.97), APOB rs1801701 (ORs = 1.72-2.13) and APOB rs1042031 (ORs = 1.66-1.88) as well as dominant model of ABCA1 rs2230806 (OR = 1.31) were significantly associated with higher risk of ischemic stroke. However, no significant associations were observed between ischemic stroke and the other five polymorphisms, namely ApoB (rs693) and APOC3 (rs4520, rs5128, rs2854116 and rs2854117), under any genetic model.

CONCLUSIONS

The present meta-analysis confirmed a significant association of APOA5 rs662799 CC, APOA5 rs3135506 CG, APOB rs1801701 GA, APOB rs1042031 GA and ABCA1 rs2230806 GG with increased risk of ischemic stroke.

Polymorphisms of MTHFR, eNOS, ACE, AGT, ApoE, PON1, PDE4D, and Ischemic Stroke: Meta-Analysis

INTRODUCTION

The association between ischemic stroke and genetic polymorphisms of methylenetetrahydrofolate reductase (MTHFR; 677C>T and 1298A>C), endothelial nitric oxide synthase (eNOS; -786T>C, +894G>T, and variable number tandem repeat [VNTR]), phosphodiesterase 4D (PDE4D; SNPs 83 and 87), angiotensin-converting enzyme (ACE) I/D, angiotensinogen (AGT) 235M>T, paraoxonase 1 (PON1) 192Q>R, and apolipoprotein E (ApoE) ε2ε3ε4 remains inconclusive. Therefore, this updated meta-analysis aimed to clarify the presumed influence of genetic polymorphisms on ischemic stroke by meta-analyzing the comprehensive coverage of all individual association studies.

METHODS

All case-control studies published in different languages such as English, Japanese, Korean, Spanish, Chinese, Hungarian, Ukrainian, or Russian were identified from databases. The pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated via fixed- and random-effect models. Sensitivity analysis, heterogeneity test, Hardy Weinberg Equilibrium, and Egger's regression analyses were performed in this study.

RESULTS

A total of 490 case-control studies with 138,592 cases and 159,314 controls were included in this meta-analysis. Pooled ORs from all the genetic models indicated that MTHFR 677TT and 1298CC, eNOS +894TT and VNTR, PDE4D SNP 83, ACE DD, AGT 235TT, PON1 192RR, and ApoE ε4 polymorphisms were increasing the risks of ischemic stroke. Nevertheless, PDE4D SNP 87 and eNOS -786T>C polymorphisms are not associated with ischemic stroke risks.

CONCLUSIONS

Hence, the evidence from this meta-analysis concluded that MTHFR (677C>T and 1298A>C), eNOS (+894G>T and VNTR), PDE4D SNP 83, ACE I/D, AGT 235M>T, PON1 192Q>R, and ApoE ε2ε3ε4 polymorphisms predispose individuals to ischemic stroke.

MTHFR (C677T) CT genotype and CT-apoE3/3 genotypic combination predisposes the risk of ischemic stroke

The predisposition to ischemic stroke (IS) might involve interactions of several genes and environmental factors. The present study was aimed to evaluate the influence of polymorphisms in methylenetetrahydrofolate reductase (MTHFR-C677T) and apolipoprotein-E (apo-E) as risk factors for IS patients in south Indian population. 200 IS patients and 193 age and sex matched controls were genotyped for MTHFR-C677T and apoE by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) method. Statistically significant association was observed for MTHFR CT genotype (IS-Pooled: OR=4.29; p=5.01×10(-5); IS-Males: OR=4.13; p=0.001; IS-Females: OR=8.62; p=0.027; IS-Large Vessel Disease (LVD)- Pooled: OR=4.14; p=0.0002) and T allele (IS-Pooled: OR=4.82; p=1.49×10(-5); IS-Males: OR=4.33; p=0.0002; IS-Females: OR=7.99; p=0.031; IS-LVD-Pooled: OR=4.13; p=0.0001). Further, reduced frequencies of CC genotype (IS-Pooled: OR=0.20; p=9.80×10(-6); IS-Males: OR=0.25; p=0.001; IS-Females: OR=0.12; p=0.027; IS-LVD-Pooled: OR=0.23; p=0.0001) and C allele (IS-Pooled: OR=0.21; p=1.49×10(-5); IS-Males: OR=0.23; p=0.0002; IS-Females: OR=0.13; p=0.031; IS-LVD-Pooled: OR=0.24; p=0.0001) were observed in IS patients than the controls. No association was observed for apoE genotypes/alleles in IS/LVD cases. Our study demonstrated the presence of risk for MTHFR CT genotype/T allele and 'CT-3/3' (n=33 vs. 5; OR=7.42; p=0.001) genotypic combination in the development of IS in south India. Further, follow-up study of these stroke cases i.e., in later stages of the disease whether they are developing the neurological disorders such as Alzheimer's Disease (AD) and vascular dementia (VaD) is needed to draw a fruitful conclusion in connection between neurological disorders and with these two polymorphisms, before translating it into clinical practice.

Recent Advances in the Genetics of Hypertension

Hypertension is a silent killer worldwide, caused by both genetic and environmental factors. Until now, genetic and genomic association studies of hypertension are reporting different degree of association on hypertension. Hence, it is essential to gather all the available information on the reported genetic loci and to determine if any biomarker(s) is/are significantly associated with hypertension. Current review concluded the potential biomarkers for hypertension, with regards to electrolyte and fluid transports, as well as sodium/potassium ions homeostasis, which are supported by the results of case-controls and meta-analyses.

The Influence of OLR1 and PCSK9 Gene Polymorphisms on Ischemic Stroke: Evidence from a Meta-Analysis

Both OLR1 and PCSK9 genes are associated with atherosclerosis, cardiovascular disease and ischemic stroke. The overall prevalence of PCSK9 rs505151 and OLR1 rs11053646 variants in ischemic stroke were 0.005 and 0.116, respectively. However, to date, association between these polymorphisms and ischemic stroke remains inconclusive. Therefore, this first meta-analysis was carried out to clarify the presumed influence of these polymorphisms on ischemic stroke. All eligible case-control and cohort studies that met the search terms were retrieved in multiple databases. Demographic and genotyping data were extracted from each study, and the meta-analysis was performed using RevMan 5.3 and Metafor R 3.2.1. The pooled odd ratios (ORs) and 95% confidence intervals (CIs) were calculated using both fixed- and random-effect models. Seven case-control studies encompassing 1897 cases and 2119 controls were critically evaluated. Pooled results from the genetic models indicated that OLR1 rs11053646 dominant (OR = 1.33, 95%  CI:1.11–1.58) and co-dominant models (OR = 1.24, 95%  CI:1.02–1.51) were significantly associated with ischemic stroke. For the PCSK9 rs505151 polymorphism, the OR of co-dominant model (OR = 1.36, 95%  CI:1.01–1.58) was found to be higher among ischemic stroke patients. In conclusion, the current meta-analysis highlighted that variant allele of OLR1 rs11053646 G > C and PCSK9 rs505151 A > G may contribute to the susceptibility risk of ischemic stroke.