GWAS-linked hot loci predict short-term functional outcome and recurrence of ischemic stroke in Chinese population.
ABSTRACT: In the past decade, an increasing number of genome-wide association studies (GWASs) have been applied to ischemic stroke (IS) susceptibility and recovery. In our study, six GWAS-linked hot loci (ALDH2 rs10744777, HDAC9 rs2107595, ABO rs532436, PATJ rs76221407, LOC105372028 rs1842681 and PTCH1 rs2236406) were selected, genotyped and analyzed in 982 IS patients from northern Chinese population, in order to explore their roles in stroke functional outcome and recurrence risk. We found that PTCH1 rs2236406 was significantly associated with functional outcome after stroke. Further logistic regression analysis revealed the variant genotype TC/CC of rs2236406 as an independent prognostic factor for poor stroke recovery in Chinese population. Meanwhile, we observed that GA/AA genotype of ABO rs532436 was statistically correlated with the increased risk of stroke recurrence, especially for patients with large-artery atherosclerosis. Moreover, multivariate Cox analysis identified ABO rs12342 as an independent predictor for IS recurrence. Further functional annotation analysis demonstrated that rs2236406 and rs2043211 were located in the transcriptionally active region, and could change the regulatory motif, transcription factor binding capacity and expression level of RP11-435O5.5 (antisense to PTCH1) and ABO, respectively. In summary, our results suggested that PTCH1 rs2236406 and ABO rs532436 may be novel genetic markers and potential therapeutic targets for stroke prognosis. More studies are required to confirm our findings and clarify the underlying molecular mechanisms.
Project description:Several recent genome-wide association studies (GWASs) have suggested that the histone deacetylase 9 (HDAC9) gene is associated with stroke, but the reliability of these findings remains controversial, particularly for the data derived from different ethnicities and geographical locations. Therefore, we performed a meta-analysis to explore the associations between HDAC9 polymorphisms and the risk of stroke in the Chinese population. All eligible case-control studies that met the search criteria were retrieved from multiple databases, and six case-control studies with a total of 2,356 stroke patients and 3,420 healthy controls were included. The pooled odds ratios (ORs) with 95% confidence intervals (95% CIs) were calculated to assess the strengths of the associations of 3 HDAC9 gene polymorphisms with stroke risk. Our results revealed statistically significant associations of the rs2107595 (T/C) polymorphism with an increased risk of stroke in the allele, codominant and dominant models. Additionally, the rs2389995 (G/A) polymorphism was found to be significantly associated with a decreased risk of stroke in all genetic models. In conclusion, this meta-analysis suggested that the T allele of rs2107595 in HDAC9 increases the risk of stroke but that the G allele of rs2389995 decreases the risk of stroke in the Chinese population.
Project description:A previous genome-wide association study showed that a single nucleotide polymorphism (SNP) rs2107595 in histone deacetylase 9 (HDAC9) gene was associated with large artery stroke (LAS) in Caucasians. Based on the similar atherosclerotic pathogenesis between LAS and coronary artery disease (CAD), we aimed to evaluate the associations of SNP rs2107595 with CAD risk and the severity of coronary atherosclerosis in a Chinese Han population, and explore the potential gene-environment interactions among SNP rs2107595 and conventional CAD risk factors. In a two-stage case-control study with a total of 2317 CAD patients and 2404 controls, the AG + AA genotypes of SNP rs2107595 were significantly associated with increased CAD risk (Adjusted odds ratio (OR) = 1.23, Padj = 0.001) and higher modified Gensini scores (Adjusted OR = 1.38, Padj < 0.001). These associations remained significant in subtype analyses for unstable angina pectoris (UAP), non-ST-segment elevation myocardial infarction (NSTEMI) and ST-segment elevation myocardial infarction (STEMI). Subgroup and multifactor dimensionality reduction analyses (MDR) further found the gene-environment interactions among SNP rs2107595, body mass index, type 2 diabetes and hyperlipidemia in CAD risk and the severity of coronary atherosclerosis. Moreover, patients with CAD had higher levels of HDAC9 mRNA expression and plasma HDAC9 than controls. Subsequent genotype-phenotype analyses observed the significant correlations of SNP rs2107595 with HDAC9 mRNA expression and plasma HDAC9 levels in controls and patients with NSTEMI and STEMI. Taken together, our data suggest that SNP rs2107595 may contribute to coronary atherosclerosis and CAD risk through a possible mechanism of regulating HDAC9 expression and gene-environment interactions.
Project description:The histone deacetylase 9 (HDAC9) polymorphism rs2107595 is associated with an increased risk for large vessel atherosclerotic stroke (LVAS). In humans, there remains a need to better understand this HDAC9 polymorphism's contribution to large vessel stroke. In this pilot study, we evaluated whether the HDAC9 polymorphism rs2107595 is associated with differences in leukocyte gene expression in patients with LVAS. HDAC9 SNP rs2107595 was genotyped in 155 patients (43 LVAS and 112 vascular risk factor controls). RNA isolated from blood was processed on whole genome microarrays. Gene expression was compared between HDAC9 risk allele-positive and risk allele-negative LVAS patients and controls. Functional analysis identified canonical pathways and molecular functions associated with rs2107595 in LVAS. In HDAC9 SNP rs2107595 risk allele-positive LVAS patients, there were 155 genes differentially expressed compared to risk allele-negative patients (fold change >?|1.2|, p?<?0.05). The 155 genes separated the risk allele-positive and risk allele-negative LVAS patients on a principal component analysis. Pathways associated with HDAC9 risk allele-positive status involved IL-6 signaling, cholesterol efflux, and platelet aggregation. These preliminary data suggest an association with the HDAC9 rs2107595 risk allele and peripheral immune, lipid, and clotting systems in LVAS. Further study is required to evaluate whether these differences are related to large vessel atherosclerosis and stroke risk.
Project description:BACKGROUND AND PURPOSE:A novel association between a single nucleotide polymorphism on chromosome 7p21.1 and large-vessel ischemic stroke was recently identified. The most likely underlying gene is histone deacetylase 9 (HDAC9). The mechanism by which HDAC9 increases stroke risk is not clear; both vascular and neuronal mechanisms have been proposed. METHODS:We determined whether the lead single nucleotide polymorphisms were associated with asymptomatic carotid plaque (N=25 179) and carotid intima-media thickness (N=31 210) detected by carotid ultrasound in a meta-analysis of population-based and community cohorts. Immunohistochemistry was used to determine whether HDAC9 was expressed in healthy human cerebral and systemic arteries. In the Tampere Vascular Study, we determined whether HDAC9 mRNA expression was altered in carotid (N=29), abdominal aortic (N=15), and femoral (N=24) atherosclerotic plaques compared with control (left internal thoracic, N=28) arteries. RESULTS:Both single nucleotide polymorphisms (rs11984041 and rs2107595) were associated with common carotid intima-media thickness (rs2107595; P=0.0018) and with presence of carotid plaque (rs2107595; P=0.0022). In both cerebral and systemic arteries, HDAC9 labeling was seen in nuclei and cytoplasm of vascular smooth muscle cells, and in endothelial cells. HDAC9 expression was upregulated in carotid plaques compared with left internal thoracic controls (P=0.00000103). It was also upregulated in aortic and femoral plaques compared with controls, with mRNA expression increased in carotid compared with femoral plaques (P=0.0038). CONCLUSIONS:Our results are consistent with the 7p21.1 association acting via promoting atherosclerosis, and consistent with alterations in HDAC9 expression mediating this increased risk. Further studies in experimental models are required to confirm this link.
Project description:Recent genome-wide association studies (GWAS) have indicated an association of histone deacetylase 9 (HDAC9) genetic variant with large-vessel stroke and coronary artery disease, among the European population. However, whether HDAC9 gene is associated with an increased susceptibility to acute coronary syndrome (ACS) in Chinese Han population is not known. A total of 472 patients, including patients with ACS (N = 309), and those with chest pain syndrome (controls, N = 163) were enrolled. Genotyping for HDAC9 gene was performed using the ligation detection reaction assay. A series of statistical analyses were performed to investigate the correlation between HDAC9 gene SNPs and the susceptibility to ACS. The results revealed a significant association of rs2240419 with ACS risk in which the A allele (P = 0.047) and the A allele carriers (AA + AG) (P = 0.037) were more likely to be in ACS group as compared to those in the control group. None of two other SNPs, rs2389995 and rs2107595, were significantly associated with ACS risk (P > 0.05). Logistic regression analyses further revealed an increased risk for ACS in A allele carrier among rs2240419 genotypes, as compared to those with GG homozygotes (odds ratio: 1.869, 95% CI 1.143, 3.056, P = 0.013). A significant correlation between rs2240419 polymorphism of HDAC9 gene and the susceptibility to ACS in Chinese Han population was observed in this study.
Project description:BACKGROUND:Histone deacetylase 9 (HDAC9) plays an important role in transcriptional regulation, cell cycle progression and developmental events; moreover, it has been investigated as a candidate gene in a number of conditions, including the onset and progression of atherosclerosis. We hypothesized that the rs2107595 HDAC9 gene polymorphism may be associated with advanced carotid artery disease in a Slovenian cohort. We also investigated the effect of this polymorphism on HDAC9 receptor expression in the internal carotid artery (ICA) specimens obtained by endarterectomy. METHODS:This case-control study enrolled 619 unrelated Slovenian patients: 311 patients with ICA stenosis >?75% as the study group and 308 patients with ICA stenosis <?50% as the control group. Patient laboratory and clinical data were obtained from the medical records. The rs2107595 polymorphisms were genotyped using TaqMan SNP Genotyping assay. HDAC9 expression was assessed by immunohistochemistry in 30 ICA specimens from patients with ICA atherosclerosis >?75%, and the numerical areal density of HDAC9 positive cells was calculated. RESULTS:The occurrence of advanced ICA atherosclerosis in the Slovenian cohort was 3.81 times higher in the codominant genetic model (OR?=?3.81, 95%CI?=?1.06-13.77, p?=?0.04), and 3.10 times higher in the recessive genetic model (OR?=?3.10, 95%CI?=?1.16-8.27, p?=?0.02). In addition, the A allele of rs2107595 was associated with increased HDAC9 expression in the ICA specimens obtained by endarterectomy. CONCLUSIONS:We observed a significant association between the AA genotype of rs2107595 with the advanced carotid artery disease in our Slovenian cohort, indicating that this polymorphism may be a genetic risk factor for ICA atherosclerosis.
Project description:Understanding the genetic risk factors for stroke is an essential step to decipher the underlying mechanisms, facilitate the identification of novel therapeutic targets, and optimize the design of prevention strategies. A very small proportion of strokes are attributable to monogenic conditions, the vast majority being multifactorial, with multiple genetic and environmental risk factors of small effect size. Genome-wide association studies and large international consortia have been instrumental in finding genetic risk factors for stroke. While initial studies identified risk loci for specific stroke subtypes, more recent studies also revealed loci associated with all stroke and all ischemic stroke. Risk loci for ischemic stroke and its subtypes have been implicated in atrial fibrillation (PITX2 and ZFHX3), coronary artery disease (ABO, chr9p21, HDAC9, and ALDH2), blood pressure (ALDH2 and HDAC9), pericyte and smooth muscle cell development (FOXF2), coagulation (HABP2), carotid plaque formation (MMP12), and neuro-inflammation (TSPAN2). For hemorrhagic stroke, two loci (APOE and PMF1) have been identified.
Project description:RATIONALE:Ischemic stroke is among the leading causes of adult disability. Part of the variability in functional outcome after stroke has been attributed to genetic factors but no locus has been consistently associated with stroke outcome. OBJECTIVE:Our aim was to identify genetic loci influencing the recovery process using accurate phenotyping to produce the largest GWAS (genome-wide association study) in ischemic stroke recovery to date. METHODS AND RESULTS:A 12-cohort, 2-phase (discovery-replication and joint) meta-analysis of GWAS included anterior-territory and previously independent ischemic stroke cases. Functional outcome was recorded using 3-month modified Rankin Scale. Analyses were adjusted for confounders such as discharge National Institutes of Health Stroke Scale. A gene-based burden test was performed. The discovery phase (n=1225) was followed by open (n=2482) and stringent joint-analyses (n=1791). Those cohorts with modified Rankin Scale recorded at time points other than 3-month or incomplete data on previous functional status were excluded in the stringent analyses. Novel variants in PATJ (Pals1-associated tight junction) gene were associated with worse functional outcome at 3-month after stroke. The top variant was rs76221407 (G allele, ?=0.40, P=1.70×10-9). CONCLUSIONS:Our results identify a set of common variants in PATJ gene associated with 3-month functional outcome at genome-wide significance level. Future studies should examine the role of PATJ in stroke recovery and consider stringent phenotyping to enrich the information captured to unveil additional stroke outcome loci.
Project description:ANRIL has long been considered as the strongest candidate gene at the 9p21 locus, robustly associated with stroke and coronary artery disease. However, the underlying molecular mechanism remains unknown. The present study works to elucidate such a mechanism.Using expression quantitative loci analysis, we identified potential genes whose expression may be influenced by genetic variation in ANRIL. To verify the identified gene(s), knockdown and overexpression of ANRIL were evaluated in human umbilical vein endothelial cells and HepG2 cells. Ischemic stroke and coronary artery disease risk were then evaluated in the gene(s) demonstrated to be mediated by ANRIL in 3 populations of Chinese Han ancestry: 2 ischemic stroke populations consisting of the Central China cohort (903 cases and 873 controls) and the Northern China cohort (816 cases and 879 controls) and 1 coronary artery disease cohort consisting of 772 patients and 873 controls.Expression quantitative loci analysis identified CARD8 among others, with knockdown of ANRIL expression decreasing CARD8 expression and overexpression of ANRIL increasing CARD8 expression. The minor T allele of a previously identified CARD8 variant (rs2043211) was found to be significantly associated with a protective effect of ischemic stroke under the recessive model in 2 independent stroke cohorts. No significant association was found between rs2043211 and coronary artery disease.CARD8 is a downstream target gene regulated by ANRIL. Single nucleotide polymorphism rs2043211 in CARD8 is significantly associated with ischemic stroke. ANRIL may increase the risk of ischemic stroke through regulation of the CARD8 pathway.
Project description:OBJECTIVE:Worldwide, the highest frequencies of APOL1-associated kidney variants are found in indigenous West Africans among whom small vessel disease (SVD) ischemic stroke is the most common stroke phenotype. The objective of this study was to investigate the association and effect sizes of 23 selected SNPs in 14 genes of relevance, including the APOL1 G1 variants, with the occurrence of SVD ischemic stroke among indigenous West African participants in the Stroke Investigative Research and Education Network (SIREN) Study. MATERIALS AND METHODS:Cases were consecutively recruited consenting adults (aged 18 years or older) with neuroimaging-confirmed first clinical stroke. Stroke-free controls were ascertained using a locally validated version of the Questionnaire for Verifying Stroke-Free Status (QVSFS). Logistic regression models adjusting for known vascular risk factors were fitted to assess the associations of the 23 SNPs in rigorously phenotyped cases (N = 154) of SVD ischemic stroke and stroke-free (N = 483) controls. RESULTS:Apolipoprotein L1 (APOL1) rs73885319 (OR = 1.52; CI: 1.09-2.13, P-value = .013), rs2383207 in CDKN2A/CDKN2B (OR = 3.08; CI: 1.15-8.26, P -value = .026) and rs2107595 (OR = 1.70; CI: 1.12-2.60, P-value = .014) and rs28688791 (OR = 1.52; CI: 1.03-2.26, P-value = .036) in HDAC9 gene were associated with SVD stroke at 0.05 significance level. Polymorphisms in other genes did not show significant associations. CONCLUSION:This is the first report of a specific association of APOL1 with a stroke subtype. Further research is needed to confirm these initial findings and deepen understanding of the genetics of stroke in people of African ancestry with possible implications for other ancestries as all humans originated from Africa.