Impact of miR-200b and miR-495 variants on the risk of large-artery atherosclerosis stroke.

Single-nucleotide polymorphisms (SNPs) of microRNAs (miRNAs) may alter miRNA transcription, maturation and target specificity, thus affecting stroke susceptibility. We aimed to investigate whether miR-200b and miR-495 SNPs may be associated with ischemic stroke (IS) risk and further explore underlying mechanisms including related genes and pathways. MiR-200b rs7549819 and miR-495 rs2281611 polymorphisms were genotyped among 712 large-artery atherosclerosis (LAA) stroke patients and 1,076 controls in a case-control study. Bioinformatic analyses were performed to explore potential association of miR-200b/495 with IS and to examine the effects of these two SNPs on miR-200b/495. Furthermore, we evaluated the association between these two SNPs and stroke using the public GWAS datasets. In our case-control study, rs7549819 was significantly associated with a decreased risk of LAA stroke (OR = 0.73, 95% CI = 0.58-0.92; p = 0.007), while rs2281611 had no significant association with LAA stroke risk. These results were consistent with the findings in East Asians from the GIGASTROKE study. Combined effects analysis revealed that individuals with 2-4 protective alleles (miR-200bC and miR-495 T) exhibited lower risk of LAA stroke than those with 0-1 variants (OR = 0.76, 95% CI = 0.61-0.96; p = 0.021). Bioinformatic analyses showed that miR-200b and miR-495 were significantly associated with genes and pathways related to IS pathogenesis, and rs7549819 and rs2281611 markedly influenced miRNA expression and structure. MiR-200b rs7549819 polymorphism and the combined genotypes of miR-200b rs7549819 and miR-495 rs2281611 polymorphisms were associated with decreased risk of LAA stroke in Chinese population.

Association of MicroRNA Biogenesis Genes Polymorphisms with Risk of Large Artery Atherosclerosis Stroke.

Convincing evidence has shown that microRNAs (miRNAs) are involved in the pathogenesis of stroke. This study aimed to examine whether miRNA biogenesis genes polymorphisms are associated with risk of large artery atherosclerosis (LAA) stroke. Three polymorphisms (DROSHA rs10719 T>C, RAN rs3803012 A>G, and PIWIL1 rs10773771 C>T) were screened by certain criteria. A total of 1,785 (710 cases and 1,075 controls) study subjects were included in this study. We found that rs10773771 CC genotype was associated with a decreased risk of LAA stroke (CC vs. TT/CT: OR 0.63, 95% CI 0.46-0.86, P = 3 × 10-3). In silico analysis suggested that rs10773771 can change the mRNA secondary structure of PIWIL1 and affect the binding of the miRNAs and regulatory motifs to the 3'-UTR of PIWIL1. Expression quantitative trait loci analysis showed that rs10773771 could change the expression of PIWIL1 in human skin (P = 1.534 × 10-10) and thyroid tissues (P = 4.869 × 10-6). These findings suggested that PIWIL1 rs10773771 may be associated with a decreased risk of LAA stroke.

The variants at FLNA and FLNB contribute to the susceptibility of hypertension and stroke with differentially expressed mRNA.

BACKGROUND: Filamin A and filamin B were involved in vascular development and remodeling. Herein, it is important to explore the associations of FLNA and FLNB variants with hypertension and stroke. METHODS: The associations of two single-nucleotide polymorphisms (SNPs) at FLNA and five SNPs at FLNB with hypertension and stroke were examined in two case-control studies and a cohort study in Chinese Han population. Risks were estimated as odds ratio (OR) and hazard ratio (HR) by Logistic and Cox regression analysis respectively. In addition, filamin B, FLNA and FLNB mRNA expression were measured. RESULTS: In the case-control study of hypertension, FLNA rs2070816 (CT + TT vs. CC) and rs2070829 (CG + GG vs. CC) were significantly associated with hypertension in <55 years group (OR = 1.338, P = 0.018; OR = 1.615, P = 0.005) and FLNB rs839240 (AG + GG vs. AA) was significantly associated with hypertension in females (OR = 0.828, P = 0.041) and nonsmokers (OR = 0.829, P = 0.020). In the follow-up study, rs2070829 GG genotype carriers presented a higher risk of hypertension than CC/CG in males (HR = 1.737, P = 0.014) and smokers (HR = 1.949, P = 0.012). In the case-control study of stroke, FLNB rs1131356 variation was significantly associated with ischemic stroke (IS) and intracerebral hemorrhage (ICH), ORs of additive model were 1.342 and 1.451, with P values of 0.001 and 0.007. The FLNA transcript 2, FLNB transcript 3, transcript 4 mRNA, and filamin B expression levels were significantly different between IS cases and hypertension controls and among the genotypes of rs839240 in hypertensive individuals (P < 0.05). CONCLUSIONS: Our findings support the genetic contribution of FLNA and FLNB to hypertension, and stroke with differentially mRNA expression.

HTRA1 Variants and the Interaction with Smoking Confer the Genetic Susceptibility to Ischemic Stroke.

High temperature requirement protein A1 (HtrA1) was identified as the causative gene of autosomal recessive arteriopathy and associated with lacunar ischemic stroke (IS) in European. This study aimed at evaluating the association of HTRA1 with IS and four tagging single-nucleotide polymorphisms (SNPs) were genotyped in a cohort of 4,098 Chinese. The mRNA level of HTRA1 in 72 IS cases and 72 hypertension controls were measured and compared. In whole population, SNP rs2268350 (C>T) was significantly associated with IS incidence (P=0.034). Stratification analysis observed significant association of rs2268350 in male, smoking and drinking populations, rs2672587 (C>G) in smoking and nonsmoking populations and rs3793917 (C>G) in smoking, nonsmoking and nondrinking populations with stroke respectively (P<0.05). The additive interaction and multiplicative interaction between rs2268350 and smoking were both of significant (P<0.05) after adjustment for the covariates. There was a cumulated risk of IS among genotypes of rs3793917 (P=0.009) and rs2672587 (P=0.047) in smoking population. The mRNA level of HTRA1 in non-smokers with rs2268350 CC was significantly higher than smokers with rs2268350 CT/TT (P=0.046) in IS cases. Our findings support that HTRA1 confers the genetic susceptibility to IS and smoking might modify the genetic effect of HTRA1 on IS by suppressing HTRA1 mRNA expression.

The impact of COVID-19 pandemic on treatment delay and short-term neurological functional prognosis for acute ischemic stroke during the lockdown period.

Background: Preventive strategies implemented during the COVID-19 pandemic may negatively influence the management of patients with acute ischemic stroke (AIS). Nowadays, studies have demonstrated that the pandemic has led to a delay in treatment among patients with AIS. Whether this delay contributes to meaningful short-term outcome differences warranted further exploration. Objective: The objective of this study was to evaluate the impacts of the COVID-19 pandemic on treatment delay and short-term outcomes of patients with AIS treated with IVT and MT. Methods: Patients admitted before (from 11/1/2019 to 1/31/2020) and during the COVID-19 pandemic (from 2/1/2020 to 3/31/2020) were screened for collecting sociodemographic data, medical history information, and symptom onset status, and comparing the effect of treatment delay. The patients treated with IVT or MT were compared for delay time and neurological outcomes. Multivariable logistic regression was used to estimate the effect of treatment delay on short-term neurological prognosis. Results: In this study, 358 patients receiving IVT were included. DTN time increased from 50 min (IQR 40-75) before to 65 min (IQR 48-84), p = 0.048. 266 patients receiving MT were included. The DTP was 120 (112-148) min vs. 160 (125-199) min before and during the pandemic, p = 0.002. Patients with stroke during the pandemic had delays in treatment due to the need for additional PPE (p < 0.001), COVID-19 screening processes (p < 0.001), multidisciplinary consultation (p < 0.001), and chest CT scans (p < 0.001). Compared with pre-COVID-19, during the pandemic, patients had a higher likelihood of spontaneous intracranial hemorrhage after IVT (OR: 1.10; 95% CI, 1.03-1.30) and a lower likelihood of mRS scores 0-2 at discharge (OR: 0.90; 95% CI, 0.78-0.99). In logistic regression analysis, high NIHSS score at admission, increasing age, worse pre-admission mRS, large vessel occlusion, admission during the lockdown period, and low mTICI grade after MT were associated with an mRS ≥ 3. Conclusion: The COVID-19 pandemic has had remarkable impacts on the management of AIS. The pandemic might exacerbate certain time delays and play a significant role in early adverse outcomes in patients with AIS.

Development and Validation of a Polygenic Risk Score for Stroke in the Chinese Population.

OBJECTIVE: To construct a polygenic risk score (PRS) for stroke and evaluate its utility in risk stratification and primary prevention for stroke. METHODS: Using a meta-analytic approach and large genome-wide association results for stroke and stroke-related traits in East Asians, we generated a combined PRS (metaPRS) by incorporating 534 genetic variants in a training set of 2,872 patients with stroke and 2,494 controls. We then validated its association with incident stroke using Cox regression models in large Chinese population-based prospective cohorts comprising 41,006 individuals. RESULTS: During a total of 367,750 person-years (mean follow-up 9.0 years), 1,227 participants developed stroke before age 80 years. Individuals with high polygenic risk had an about 2-fold higher risk of incident stroke compared with those with low polygenic risk (hazard ratio [HR] 1.99, 95% confidence interval [CI] 1.66-2.38), with the lifetime risk of stroke being 25.2% (95% CI 22.5%-27.7%) and 13.6% (95% CI 11.6%-15.5%), respectively. Individuals with both high polygenic risk and family history displayed lifetime risk as high as 41.1% (95% CI 31.4%-49.5%). Individuals with high polygenic risk achieved greater benefits in terms of absolute risk reductions from adherence to ideal fasting blood glucose and total cholesterol than those with low polygenic risk. Maintaining favorable cardiovascular health (CVH) profile could substantially mitigate the increased risk conferred by high polygenic risk to the level of low polygenic risk (from 34.6% to 13.2%). CONCLUSIONS: Our metaPRS has great potential for risk stratification of stroke and identification of individuals who may benefit more from maintaining ideal CVH. CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that metaPRS is predictive of stroke risk.

Association of DIAPH1 gene polymorphisms with ischemic stroke.

DIAPH1 is a formin protein involved in actin polymerization with important roles in vascular remodeling and thrombosis. To investigate potential associations of DIAPH1 single-nucleotide polymorphisms (SNPs) with hypertension and stroke, 2,012 patients with hypertension and 2,210 controls, 2,966 stroke cases [2,212 ischemic stroke (IS), 754 hemorrhagic stroke (HS)] and 2,590 controls were enrolled respectively in the case-control study. A total of 4,098 individual were included in the cohort study. DIAPH1 mRNA expression was compared between 66 IS [43 small artery occlusion (SAO) and 23 large-artery atherosclerosis (LAA)] and 58 controls. Odds ratio (OR), hazard ratio (HR) and 95% confidence interval (CI) were calculated by logistic and cox regression analysis. Rs7703688 T>C variation was significantly associated with an increased risk of IS [OR (95% CI) was 1.721 (1.486-1.993), P=4.139×10-12]. Association of rs7703688 with stroke risk was further validated in the cohort study [adjusted HRs (95% CIs) for additive and recessive models were 1.385 (1.001-1.918), P=0.049, and 2.882 (1.038-8.004), P=0.042, respectively)]. DIAPH1 mRNA expression was significantly downregulated in IS. In SAO stroke subtype, DIAPH1 expression has an increased trend among rs251019 genotypes (Ptrend=0.048). These novel findings suggest that DIAPH1 variation contributes to genetic susceptibility to stroke risk, especially the SAO subtype of IS.

A comprehensive contribution of genetic variations of the insulin-like growth factor 1 signalling pathway to stroke susceptibility.

BACKGROUND AND AIMS: The insulin-like growth factor (IGF)-1 signalling pathway has been implicated in the pathogenesis of atherosclerosis; however, the mechanism underlying its role in stroke remains unexplained. Herein, we aimed to explore the effects of genetic polymorphisms in the IGF1 pathway on stroke in the Chinese Han population. METHODS: Twenty-six single-nucleotide polymorphisms (SNPs) in IGF1 pathway genes were genotyped in a case-control study consisting of 2070 stroke cases and 2243 controls. Main genetic effects and gene-gene interactive effects of the IGF1 pathway were evaluated. Weighted genetic risk scores (wGRS) were computed, and the associations between wGRS and gene expression were analysed. RESULTS: The variants at GHRH rs6032470 were significantly associated with high risk of hemorrhagic stroke (HS), and the adjusted OR (95%CI) was 1.368 (1.136-1.647). Significant additive interaction between rs6032470 and gender was detected for HS and ischemic stroke (IS). The association of rs6032470 and stroke was stronger in males than in females. Additionally, a significant gene-gene interaction of rs6032470-rs1874479 (IGFBP1) in relation to HS risk was identified (p < 0.05). IGF1 mRNA expression was significantly upregulated in IS, while it was linearly downregulated across rs6214 genotypes. In addition, IGFBP3 transcript variant 2 mRNA level was negatively correlated with wGRS (r = -0.285, p = 0.005). CONCLUSIONS: Our findings indicated that the IGF1 signalling pathway genes potentiated the risk of stroke through both main effects and gene-gene interactions. The genetic effect of GHRH rs6032470 on stroke was gender dependent. The wGRS of IGF1 pathway genes may be an independent predictor of stroke risk.

Histone deacetylase 6 interference protects mice against experimental stroke-induced brain injury via activating Nrf2/HO-1 pathway.

Cerebral stroke is a fatal disease with increasing incidence. The study was to investigate the role and mechanism of Histone deacetylase 6 (HDAC6) on experimental stroke-induced brain injury. The recombinant shRNA-HDAC6 or scramble shRNA lentivirus was transfected to ICR mice. Then, the ischemia/reperfusion injury (I/RI) mice were constructed using middle cerebral artery occlusion (MCAO) method. Brain TTC staining was used to determine infarct areas. Serum levels of oxidative stress-related factors were detected by enzyme linked immunosorbnent assay (ELISA). Realtime-qPCR (RT-qPCR) and Western blot were used to respectively detect mRNA and protein levels. HDAC6 was up-regulated in brain I/RI mice (MCAO group), and down-regulated again in MCAO mice transfected with shRNA-HDAC6 (MCAO + shRNA group). The infarct area of the MCAO mice was increased, neurological scores were higher, and serum protein levels of 3-NT, 4-HNE and 8-OHdG were higher. HDAC6 interference attenuated above effects. Though protein levels of Nrf2 and HO-1 in cytoplasm increased slightly in MCAO group, they increased significantly by HDAC6 interference. The protein levels of Nrf2 in cytoblast decreased significantly in MCAO group, and increased markedly by HDAC6 interference. HDAC6 interference protected mice against experimental stroke-induced brain injury via Nrf2/HO-1 pathway.