Angiotensin-converting enzyme polymorphisms and risk of spontaneous deep intracranial hemorrhage in Taiwan

Genetics of Spontaneous Intracerebral Hemorrhage: Risk and Outcome

Spontaneous intracerebral hemorrhage (ICH) is a common fatal event without an effective therapy. Of note, some familial aggregation and inherited tendency is found in ICH and heritability estimates indicate that genetic variations contribute substantially to ICH risk and outcome. Thus, identification of genetic variants that affect the occurrence and outcome may be helpful for ICH prevention and therapy. There are several reviews summarizing numerous genetic variants associated with the occurrence of ICH before, but genetic variants contributing to location distribution and outcome have rarely been introduced. Here, we summarize the current knowledge of genetic variants and pay special attention to location distribution and outcome. So far, investigations have reveled variations in APOE, GPX1, CR1, ITGAV, PRKCH, and 12q21.1 are associated with lobar ICH (LICH), while ACE, COL4A2, 1q22, TIMP1, TIMP2, MMP2, MMP9, and TNF are associated with deep ICH (DICH). Moreover, variations in APOE, VWF, 17p12, HP, CFH, IL6ST, and COL4A1 are possible genetic contributors to ICH outcome. Furthermore, the prospects for ICH related genetic studies from the bench to the bed were discussed.

Human Galectin-7 Gene LGALS7 Promoter Sequence Polymorphisms and Risk of Spontaneous Intracerebral Hemorrhage: A Prospective Study

Background and purpose

Despite evidence for the role of genetic factors in stroke, only a small proportion of strokes have been clearly attributed to monogenic factors, due to phenotypic heterogeneity. The goal of this study was to determine whether a significant relationship exists between human galectin-7 gene LGALS7 promoter region polymorphisms and the risk of stroke due to non-traumatic intracerebral hemorrhage (ICH).

Methods

This two-stage genetic association study included an initial exploratory stage followed by a discovery stage. During the exploratory stage, transgenic galectin-7 mice or transgenic mice with the scrambled sequence of the hairpin structure –silenced down gene LGALS7—were generated and then expressed differentially expressed proteins and galectin-7-interacting proteins were identified through proteomic analysis. During the discovery stage, a single-nucleotide polymorphism (SNP) genotyping approach was used to determine associations between 2 LGALS7 SNPs and ICH stroke risk for a cohort of 24 patients with stroke of the Chinese Han population and 70 controls.

Results

During the exploratory phase, LGALS7 expression was found to be decreased in TGLGALS–DOWN mice as compared to its expression in TGLGALS mice. During the discovery phase, analysis of LGALS7 sequences of 24 non-traumatic ICH cases and 70 controls led to the identification of 2 ICH susceptibility loci: a genomic region on 19q13.2 containing two LGALS7 SNPs, rs567785577 and rs138945880, whereby the A allele of rs567785577 and the T allele of rs138945880 were associated with greater risk of contracting ICH [for T and A vs. C and G, unadjusted odds ratio (OR) = 13.5; 95% CI = 2.249–146.5; p = 0.002]. This is the first study to genotype the galectin-7 promoter in patients with hemorrhagic stroke. Genotype and allele association tests and preliminary analysis of patients with stroke revealed that a single locus may be a genetic risk factor for hemorrhagic stroke.

Conclusion

A and T alleles of two novel SNP loci of 19q13.2, rs567785577 and rs138945880, respectively, were evaluated for associations with susceptibility to ICH. Further studies with expanded case numbers that include subjects of other ethnic populations are needed to elucidate mechanisms underlying associations between these SNPs and ICH risk.

Association between Angiotensin Converting Enzyme Insertion/Deletion gene polymorphism with the risk of Hemorrhagic Stroke: A systematic review and Meta-Analysis of 53 studies

BACKGROUND AND AIMS

Hemorrhagic stroke (HS) results in significant mortality and disability worldwide. Angiotensin Converting Enzyme (ACE) is responsible for blood pressure regulation and vascular homeostasis. Our objective was to conduct a comprehensive meta-analysis for ascertaining the association of ACE I/D polymorphism with HS since a number of studies depicted inconclusive evidence.

METHODS

Literature search was performed till July 10, 2020 in PubMed, EMBASE, Cochrane, Chinese National Knowledge Information and Google Scholar databases with keywords: ('Angiotensin Converting Enzyme' OR 'ACE') AND ('Single Nucleotide polymorphisms' OR 'SNP') AND ('Hemorrhagic stroke or 'HS'). Pooled Odds Ratio (OR) and 95% Confidence Interval (CI) were determined for gene-disease association using either fixed (when I² < 50%) or random effect (when I² > 50%) models. Risk of bias in studies was assessed using funnel plots and sensitivity analyses. Statistical analysis was performed using STATA version 13.0 software.

RESULTS

A total of 53 studies having 5186 HS and 7347 healthy control subjects were included in our meta-analysis. Pooled analyses showed that ACE I/D gene polymorphism had significant association with risk of HS in overall study population [(dominant model: OR = 1.29, 95% CI = 1.12-1.50 & recessive model: OR = 1.79, 95% CI = 1.46-2.20)]. Population subgroup analyses further revealed significant relationship of ACE I/D polymorphism with ICH in Asians (recessive: OR 1.97, 95% CI = 1.57-2.47) but not in Caucasians (recessive: OR 1.02, 95% CI = 0.76-1.36).

CONCLUSION

This meta-analysis suggests that ACE I/D polymorphism may lead to risk of HS and can be a potential biomarker for HS susceptibility especially in Asian population.

Genetic risk of Spontaneous intracerebral hemorrhage: Systematic review and future directions

BACKGROUND

Although highly heritable, few genes have been linked to spontaneous intracerebral hemorrhage (SICH), which does not currently have any evidence-based disease-modifying therapy. Individuals of African ancestry are especially susceptible to SICH, even more so for indigenous Africans. We systematically reviewed the genetic variants associated with SICH and examined opportunities for rapidly advancing SICH genomic research for precision medicine.

METHOD

We searched the National Human Genome Research Institute-European Bioinformatics Institute (NHGRI-EBI) Genome Wide Association Study (GWAS) catalog and PubMed for original research articles on genetic variants associated with SICH as of 15 June 2019 using the PRISMA guideline.

RESULTS

Eight hundred and sixty-four articles were identified using pre-specified search criteria, of which 64 met the study inclusion criteria. Among eligible articles, only 9 utilized GWAS approach while the rest were candidate gene studies. Thirty-eight genetic loci were found to be variously associated with the risk of SICH, hematoma volume, functional outcome and mortality, out of which 8 were from GWAS including APOE, CR1, KCNK17, 1q22, CETP, STYK1, COL4A2 and 17p12. None of the studies included indigenous Africans.

CONCLUSION

Given this limited information on the genetic contributors to SICH, more genomic studies are needed to provide additional insights into the pathophysiology of SICH, and develop targeted preventive and therapeutic strategies. This call for additional investigation of the pathogenesis of SICH is likely to yield more discoveries in the unexplored indigenous African populations which also have a greater predilection.

Genetic Polymorphisms Associated with Spontaneous Intracerebral Hemorrhage

Differences in the incidence of spontaneous intracerebral hemorrhage (ICH) between ethnicities exist, with an estimated 42% of the variance explained by ethnicity itself. Caucasians have a higher proportion of lobar ICH (LICH, 15.4% of all ICH) than do Asians (3.4%). Alterations in the causal factor exposure between countries justify part of the ethnic variance in ICH incidence. One third of ICH risk can be explained by genetic variation; therefore, genetic differences between populations can partly explain the difference in ICH incidence. In this paper, we review the current knowledge of genetic variants associated with ICH in multiple ethnicities. Candidate gene variants reportedly associated with ICH were involved in the potential pathways of hypertension, vessel wall integrity, lipid metabolism, endothelial dysfunction, inflammation, platelet function, and coagulopathy. Furthermore, variations in APOE (in multiple ethnicities), PMF1/SLC25A44 (in European), ACE (in Asian), MTHFR (in multiple ethnicities), TRHDE (in European), and COL4A2 (in European) were the most convincingly associated with ICH. The majority of the associated genes provide small contributions to ICH risk, with few of them being replicated in multiple ethnicities.

Association between diabetes mellitus and the occurrence and outcome of intracerebral hemorrhage

OBJECTIVE

Whether diabetes mellitus (DM) is a risk factor for spontaneous intracerebral hemorrhage (ICH) and influences outcome after ICH remains unclear.

METHODS

One reviewer searched Ovid MEDLINE and Embase 1980-2014 inclusive for studies investigating the associations between DM and ICH occurrence or DM and ICH case fatality. Two reviewers independently confirmed each study's eligibility, assessed risk of bias, and extracted data. One reviewer combined studies using random effects meta-analysis.

RESULTS

Nineteen case-control studies involving 3,397 people with ICH and 5,747 people without ICH found an association between DM and ICH occurrence (unadjusted odds ratio [OR] 1.23, 95% confidence interval [CI] 1.04-1.45; I(2) = 22%), which did not differ between 17 hospital-based and 2 population-based studies (pdiff = 0.70), and was similar in the 16 studies that controlled for age and sex (unadjusted OR 1.15, 95% CI 0.95-1.40; I(2) = 14%). This association was not identified in 3 population-based cohort studies in which ICH occurred in 38 (0.66%) of 5,724 people with DM and 448 (0.57%) of 78,702 people without DM (unadjusted risk ratio [RR] 1.27, 95% CI 0.68-2.36; I(2) = 69%). DM was associated with a higher case fatality by 30 days or hospital discharge in 18 cohort studies involving 813 people with DM and 3,714 people without DM (unadjusted RR 1.52, 95% CI 1.28-1.81; I(2) = 49%).

CONCLUSIONS

The findings suggest that there may be modest associations between DM and ICH occurrence and outcome, but further information from large, population-based studies that account for confounding is required before the association can be confirmed.

Polymorphisms in the Promoters of the MMP-2 and TIMP-2 Genes Are Associated with Spontaneous Deep Intracerebral Hemorrhage in the Taiwan Population

Background

Spontaneous intracerebral hemorrhage (ICH) is a devastating stroke subtype. Matrix metalloproteinases (MMPs) function in the degradation of extracellular matrix and the activities of MMPs are modulated by their endogenous inhibitors, tissue inhibitors of metalloproteinases (TIMPs). This study aimed to discuss relationship of MMP-2 and TIMP-2 to spontaneous deep ICH (SDICH) susceptibility and hematoma size.

Methods

Associations were tested by logistic regression and general linear models (GLM) where appropriate, adjusting with covariables of age, sex, hypertension, diabetes mellitus, smoking, and alcohol consumption. Association analyses were performed first by stratification of genders and then by the age of 65 years old (y/o). Elder population was defined as subjects who were older than 65 y/o.

Results

There were 396 SDICH patients and 376 control subjects in this study. In the elder group, rs7503607 C>A variant in TIMP-2 was associated with SDICH in male and overall patients (OR = 3.49, 95% CI 1.45 to 8.40, P = 0.005 and OR = 2.45, 95% CI 1.37 to 4.38, P = 0.003, respectively) in additive genetic model. In recessive genetic model, rs2285053 TT genotype in MMP-2 was correlated to SDICH in male patients and overall elder group (OR = 7.30, 95% CI 1.3 to 40, P = 0.02 and OR = 2.91, 95% CI 1.02 to 8.31, P = 0.046, respectively), and rs7503726 AA genotype in TIMP-2 was associated with SDICH in female patients (OR = 0.29, 95% CI 0.1 to 0.84, P = 0.02). In younger male and overall younger patients, SDICH patients who had supratentorial hemorrhage had significantly lower frequency of AA genotypes in rs7503726 than those with infratentorial hemorrhage (OR = 0.36, 95% CI 0.17 to 0.75, P = 0.006 and OR = 0.43, 95% CI 0.22 to 0.84, P = 0.014, respectively). Hemorrhage size increased by 9.7 (95% CI 2.1 to 43, P = 0.004) cm³ per minor allele (A) of the rs7503607 variant in the elder female patients and increased by 4.3 (95% CI 1.4 to 12.9, P = 0.009) cm³ per minor allele (A) in all elder patients. In younger patients, the hemorrhage size decreased by 3.3 (95% CI 1.2 to 9.5, P = 0.03) cm³ per minor allele of the s7503726 variant in the female patients.

Conclusions

This study showed a significant association between the variants of MMP-2 and TIMP-2 promoters and SDICH susceptibility with significant age and gender differences. Hemorrhage location and size might be affected by TIMP-2 promoter variants in the SDICH patients.

Angiotensin-converting enzyme insertion/deletion gene polymorphism and risk of intracranial aneurysm in a Chinese population

Objective

The relationship between angiotensin-converting enzyme (ACE) insertion/deletion (I/D) gene polymorphisms and intracranial aneurysm (IA) has been studied in Caucasian and Japanese populations. The present study aimed to investigate this association in a Chinese population.

Methods

Patients with confirmed IA and age- and sex-matched control subjects without evidence of IA were enrolled. ACE I/D gene polymorphisms were analysed using polymerase chain reaction–restriction fragment length polymorphism.

Results

A total of 220 patients with IA and 220 matched controls were enrolled. In the IA group, 64, 106 and 50 patients were of the II, ID and DD genotypes, respectively, compared with 44, 99 and 77 subjects in the control group. The ACE DD genotype and D allele frequencies were significantly lower in the IA group compared with the control group. There were no statistically significant differences in the site, shape, size and Fisher Grade of aneurysms between genotypes in patients with IA.

Conclusion

The ACE DD genotype may be a protective factor for IA in a Chinese population.

Genetic Associations of Angiotensin-Converting Enzyme with Primary Intracerebral Hemorrhage: A Meta-analysis

Background

A number of studies have reported an association of angiotensin-converting enzyme (ACE) gene polymorphism with primary intracerebral hemorrhage (PICH), however the reports have demonstrated inconclusive results. To clarify this conflict, we updated the previously performed meta-analysis by Peck et al., which revealed negative results, by investigating the ACE polymorphism and its correlation to PICH.

Methods

PubMed and Embase databases (through Dec 2012) were searched for English articles on the relationship of the I/D polymorphism in ACE with PICH in humans. Summary odds ratios (ORs) were estimated and potential sources of heterogeneity and bias were explored.

Results

A total of 805 PICH cases and 1641 control cases obtained from 8 case-control studies were included. The results suggest that in dominant genetic models, the ACE I/D polymorphic variant was associated with a 58% increase in susceptibility risk of PICH (OR = 1.58; 95% CI = 1.07–2.35 for DD vs. DI+II). However, in the subgroup analysis based on race, a significant increased risk was found in Asian DD homozygote carriers (OR = 1.76 and 95% CI = 1.16–2.66 for DD vs. DI+II), but not in Caucasian DD homozygote carriers (OR = 1.18, 95% CI = 0.36–3.88, P = 0.784 for DD vs. DI+II). The heterogeneity between studies was remarkable, and its major sources of heterogeneity were due to the year in which the study was published. No potential publication bias was observed in dominant genetic models.

Conclusions

These data demonstrated evidence of a positive association between ACE I/D polymorphism with PICH, and suggested that the ACE gene is a PICH susceptible gene in Asian populations.

Angiotensin-converting enzyme insertion/deletion gene polymorphisms and risk of intracerebral hemorrhage: a meta-analysis of epidemiologic studies

Studies investigating the association between the intron 16 insertion/deletion (I/D) polymorphism (rs4646994) in the angiotensin-converting enzyme (ACE) gene and risk of intracerebral hemorrhage (ICH) have reported conflicting results. We here performed a meta-analysis based on the evidence currently available from the literature to make a more precise estimation of this relationship. Published literature from the National Library of Medline and Embase databases were retrieved. Odds ratios (OR) and 95% confidence limits (CLs) were calculated in fixed- or random-effects models when appropriate. Subgroup analyses were performed by race. This meta-analysis included six case-control studies, which included 744 ICH cases and 1411 controls. The combined results based on all studies showed that ICH cases had a significantly lower frequency of ID genotype (OR (codominant model) = 0.43, 95% CL = 0.22, 0.84, p = 0.01). In the subgroup analysis by race, we found that ICH cases had a significantly lower frequency of II genotype in Asians (OR (recessive model) = 0.50, 95% CL = 0.38, 0.66, p < 0.001; OR (codominant model) = 0.25, 95% CL = 0.09, 0.71, p = 0.009). In conclusion, our meta-analysis suggests that ACE I/D polymorphisms are associated with ICH, especially in Asians.

Association of TNF-alpha gene with spontaneous deep intracerebral hemorrhage in the Taiwan population: a case control study

Background

Genetic factors may play a role in susceptibility to spontaneous deep intracerebral hemorrhage (SDICH). Previous studies have shown that TNF-α gene variation was associated with risks of subarachnoid hemorrhage in multiple ethnicities. The present case-control study tested the hypothesis that genetic variations of the TNF-α gene may affect the risk of Taiwanese SDICH. We examined the association of SDICH risks with four single nucleotide polymorphisms (SNPs) within the TNF-α gene promoter, namely T-1031C, C-863A, C-857T, and G-308A.

Methods

Genotyping was determined by PCR-based restriction and electrophoresis assay for 260 SDICH patients and 368 controls. Associations were tested by logistic regression or general linear models with adjusting for multiple covariables in each gender group, and then in combined. Multiplicative terms of gender and each of the four SNPs were applied to detect the interaction effects on SDICH risks. To account for the multiple testing, permutation testing of 1,000 replicates was performed for empirical estimates.

Results

In an additive model, SDICH risks were positively associated with the minor alleles -1031C and -308A in men (OR = 1.9, 95% CI 1.1 to 3.4, p = 0.03 and OR = 2.6, 95% CI 1.3 to 5.3, p = 0.005, respectively) but inversely associated with -863A in females (OR = 0.5, 95% CI 0.2 to 0.9, p = 0.03). There were significant interaction effects between gender and SNP on SDICH risks regarding SNPs T-1031C, C-863A, and G-308A (p = 0.005, 0.005, and 0.007, respectively). Hemorrhage size was inversely associated with -857T in males (p = 0.04).

Conclusions

In the Taiwan population, the associations of genetic variations in the TNF-α gene promoter with SDICH risks are gender-dependent.

Analyses of interaction effect between apolipoprotein E polymorphism and alcohol use as well as cholesterol concentrations on spontaneous deep intracerebral hemorrhage in the Taiwan population

BACKGROUND

To determine the interaction effect between APOE polymorphism and lipid concentrations and alcohol use on spontaneous deep intracerebral hemorrhage (SDICH) risks.

METHODS

We enrolled 217 SDICH patients and 280 controls. Anthropometrics, personal history, and concentrations of total cholesterol (TC), high-density lipoprotein cholesterol, low-density lipoprotein cholesterol (LDL-c), and triglyceride were collected. Genotyping was determined by PCR-based restriction and electrophoresis assay. Associations were tested adjusting for multiple covariables.

RESULTS

Compared with the commonest genotype epsilon 3 epsilon 3, epsilon 2 epsilon 3 was inversely associated with TC (p=0.023) and LDL-c concentrations (p=0.005) in women. No APOE-alcohol interaction effect on lipids concentration was found. However, in men, there was a marginal effect of interaction between alcohol and APOE genotype epsilon 2 epsilon 3 vs. epsilon 3 epsilon 3 on SDICH risks (p=0.003), which is independent of TC concentration. In the male non-alcohol group, SDICH proportion was lower in the subjects carrying APOE epsilon 2 epsilon 3 (27.6%) than in those with epsilon 3 epsilon 3 (41.1%). In contrast, in the male alcohol consumption group, APOE epsilon 2 epsilon 3 was associated with a higher SDICH rate (77.8%) compared to epsilon 3 epsilon 3 (58.0%).

CONCLUSIONS

Male subjects carrying genotype epsilon 2 epsilon 3 tend to have a higher SDICH risk than those who have epsilon 3 epsilon 3 when they have alcohol exposure, but may have more benefit from alcohol abstinence.