| 1. |
- Pulit, SL, et al.
(författare)
-
Loci associated with ischaemic stroke and its subtypes (SiGN): a genome-wide association study.
- 2016
-
Ingår i: The Lancet. Neurology. - 1474-4465. ; 15:2, s. 174-84
-
Tidskriftsartikel (refereegranskat)abstract
- The discovery of disease-associated loci through genome-wide association studies (GWAS) is the leading genetic approach to the identification of novel biological pathways underlying diseases in humans. Until recently, GWAS in ischaemic stroke have been limited by small sample sizes and have yielded few loci associated with ischaemic stroke. We did a large-scale GWAS to identify additional susceptibility genes for stroke and its subtypes.To identify genetic loci associated with ischaemic stroke, we did a two-stage GWAS. In the first stage, we included 16851 cases with state-of-the-art phenotyping data and 32473 stroke-free controls. Cases were aged 16 to 104 years, recruited between 1989 and 2012, and subtypes of ischaemic stroke were recorded by centrally trained and certified investigators who used the web-based protocol, Causative Classification of Stroke (CCS). We constructed case-control strata by identifying samples that were genotyped on nearly identical arrays and were of similar genetic ancestral background. We cleaned and imputed data by use of dense imputation reference panels generated from whole-genome sequence data. We did genome-wide testing to identify stroke-associated loci within each stratum for each available phenotype, and we combined summary-level results using inverse variance-weighted fixed-effects meta-analysis. In the second stage, we did in-silico lookups of 1372 single nucleotide polymorphisms identified from the first stage GWAS in 20941 cases and 364736 unique stroke-free controls. The ischaemic stroke subtypes of these cases had previously been established with the Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification system, in accordance with local standards. Results from the two stages were then jointly analysed in a final meta-analysis.We identified a novel locus (G allele at rs12122341) at 1p13.2 near TSPAN2 that was associated with large artery atherosclerosis-related stroke (first stage odds ratio [OR] 1·21, 95% CI 1·13-1·30, p=4·50×10(-8); joint OR 1·19, 1·12-1·26, p=1·30×10(-9)). Our results also supported robust associations with ischaemic stroke for four other loci that have been reported in previous studies, including PITX2 (first stage OR 1·39, 1·29-1·49, p=3·26×10(-19); joint OR 1·37, 1·30-1·45, p=2·79×10(-32)) and ZFHX3 (first stage OR 1·19, 1·11-1·27, p=2·93×10(-7); joint OR 1·17, 1·11-1·23, p=2·29×10(-10)) for cardioembolic stroke, and HDAC9 (first stage OR 1·29, 1·18-1·42, p=3·50×10(-8); joint OR 1·24, 1·15-1·33, p=4·52×10(-9)) for large artery atherosclerosis stroke. The 12q24 locus near ALDH2, which has previously been associated with all ischaemic stroke but not with any specific subtype, exceeded genome-wide significance in the meta-analysis of small artery stroke (first stage OR 1·20, 1·12-1·28, p=6·82×10(-8); joint OR 1·17, 1·11-1·23, p=2·92×10(-9)). Other loci associated with stroke in previous studies, including NINJ2, were not confirmed.Our results suggest that all ischaemic stroke-related loci previously implicated by GWAS are subtype specific. We identified a novel gene associated with large artery atherosclerosis stroke susceptibility. Follow-up studies will be necessary to establish whether the locus near TSPAN2 can be a target for a novel therapeutic approach to stroke prevention. In view of the subtype-specificity of the associations detected, the rich phenotyping data available in the Stroke Genetics Network (SiGN) are likely to be crucial for further genetic discoveries related to ischaemic stroke.US National Institute of Neurological Disorders and Stroke, National Institutes of Health.
|
|
| 2. |
- Georgakis, Marios K., et al.
(författare)
-
Circulating Monocyte Chemoattractant Protein-1 and Risk of Stroke : Meta-Analysis of Population-Based Studies Involving 17 180 Individuals
- 2019
-
Ingår i: Circulation Research. - 0009-7330. ; 125:8, s. 773-782
-
Tidskriftsartikel (refereegranskat)abstract
- Rationale: Proinflammatory cytokines have been identified as potential targets for lowering vascular risk. Experimental evidence and Mendelian randomization suggest a role of MCP-1 (monocyte chemoattractant protein-1) in atherosclerosis and stroke. However, data from large-scale observational studies are lacking. Objective: To determine whether circulating levels of MCP-1 are associated with risk of incident stroke in the general population. Methods and Results: We used previously unpublished data on 17 180 stroke-free individuals (mean age, 56.7±8.1 years; 48.8% men) from 6 population-based prospective cohort studies and explored associations between baseline circulating MCP-1 levels and risk of any stroke, ischemic stroke, and hemorrhagic stroke during a mean follow-up interval of 16.3 years (280 522 person-years at risk; 1435 incident stroke events). We applied Cox proportional-hazards models and pooled hazard ratios (HRs) using random-effects meta-analyses. After adjustments for age, sex, race, and vascular risk factors, higher MCP-1 levels were associated with increased risk of any stroke (HR per 1-SD increment in ln-transformed MCP-1, 1.07; 95% CI, 1.01-1.14). Focusing on stroke subtypes, we found a significant association between baseline MCP-1 levels and higher risk of ischemic stroke (HR, 1.11 [1.02-1.21]) but not hemorrhagic stroke (HR, 1.02 [0.82-1.29]). The results followed a dose-response pattern with a higher risk of ischemic stroke among individuals in the upper quartiles of MCP-1 levels as compared with the first quartile (HRs, second quartile: 1.19 [1.00-1.42]; third quartile: 1.35 [1.14-1.59]; fourth quartile: 1.38 [1.07-1.77]). There was no indication for heterogeneity across studies, and in a subsample of 4 studies (12 516 individuals), the risk estimates were stable after additional adjustments for circulating levels of IL (interleukin)-6 and high-sensitivity CRP (C-reactive protein). Conclusions: Higher circulating levels of MCP-1 are associated with increased long-term risk of stroke. Our findings along with genetic and experimental evidence suggest that MCP-1 signaling might represent a therapeutic target to lower stroke risk.Visual Overview: An online visual overview is available for this article.
|
|
| 3. |
- Rannikmäe, Kristiina, et al.
(författare)
-
COL4A2 is associated with lacunar ischemic stroke and deep ICH: Meta-analyses among 21,500 cases and 40,600 controls.
- 2017
-
Ingår i: Neurology. - 1526-632X .- 0028-3878. ; 89:17, s. 1829-1839
-
Tidskriftsartikel (refereegranskat)abstract
- To determine whether common variants in familial cerebral small vessel disease (SVD) genes confer risk of sporadic cerebral SVD.We meta-analyzed genotype data from individuals of European ancestry to determine associations of common single nucleotide polymorphisms (SNPs) in 6 familial cerebral SVD genes (COL4A1, COL4A2, NOTCH3, HTRA1, TREX1, and CECR1) with intracerebral hemorrhage (ICH) (deep, lobar, all; 1,878 cases, 2,830 controls) and ischemic stroke (IS) (lacunar, cardioembolic, large vessel disease, all; 19,569 cases, 37,853 controls). We applied data quality filters and set statistical significance thresholds accounting for linkage disequilibrium and multiple testing.A locus in COL4A2 was associated (significance threshold p < 3.5 × 10-4) with both lacunar IS (lead SNP rs9515201: odds ratio [OR] 1.17, 95% confidence interval [CI] 1.11-1.24, p = 6.62 × 10-8) and deep ICH (lead SNP rs4771674: OR 1.28, 95% CI 1.13-1.44, p = 5.76 × 10-5). A SNP in HTRA1 was associated (significance threshold p < 5.5 × 10-4) with lacunar IS (rs79043147: OR 1.23, 95% CI 1.10-1.37, p = 1.90 × 10-4) and less robustly with deep ICH. There was no clear evidence for association of common variants in either COL4A2 or HTRA1 with non-SVD strokes or in any of the other genes with any stroke phenotype.These results provide evidence of shared genetic determinants and suggest common pathophysiologic mechanisms of distinct ischemic and hemorrhagic cerebral SVD stroke phenotypes, offering new insights into the causal mechanisms of cerebral SVD.
|
|
| 4. |
- Berntsson, John, et al.
(författare)
-
Increased vascular endothelial growth factor D is associated with atrial fibrillation and ischaemic stroke
- 2019
-
Ingår i: Heart. - : BMJ. - 1355-6037 .- 1468-201X. ; 105:7, s. 553-558
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: Vascular endothelial growth factor D (VEGF-D) has important functions in lymphangiogenesis and angiogenesis. High plasma levels of VEGF-D have been associated with incidence of heart failure. The association of VEGF-D with atrial fibrillation (AF) and stroke is unclear and we hypothesised that VEGF-D could also be associated with incidence of AF and ischaemic stroke. Methods: VEGF-D was measured in fasting blood samples of 4689 subjects (40% men) without a history of AF from the Malmö Diet and Cancer Study, a prospective, population-based study in Sweden. Median age was 58 years (range 46-68). Cox regression analyses, adjusted for multiple risk factors, was used to assess AF and ischaemic stroke risk in relation to VEGF-D levels. Results: During a median follow-up time of 20.6 years, there were 637 cases of incident AF and 322 cases of first ischaemic stroke. After adjustment, VEGF-D was significantly associated with AF (HR 1.13(95% CI 1.04 to 1.23) per 1 SD increase) and ischaemic stroke (HR 1.14(95% CI 1.02 to 1.28) per 1 SD). The association with ischaemic stroke was explained by an increased incidence of AF-related stroke. HRs per 1 SD were 1.34 (95% CI 1.04 to 1.71) for AF-related ischaemic stroke and 1.04 (95% CI 0.90 to 1.19) for ischaemic stroke without AF. Conclusions: Increased VEGF-D concentrations were associated with AF and ischaemic stroke. The relationship with ischaemic stroke was more pronounced in subjects with a diagnosis of AF.
|
|
| 5. |
- Gerdin, Linda, et al.
(författare)
-
The Swedish Crohn Trial: A Prematurely Terminated Randomized Controlled Trial of Thiopurines or Open Surgery for Primary Treatment of Ileocaecal Crohns Disease
- 2016
-
Ingår i: Journal of Crohn's & Colitis. - : OXFORD UNIV PRESS. - 1873-9946 .- 1876-4479. ; 10:1, s. 50-54
-
Tidskriftsartikel (refereegranskat)abstract
- Background and aims: The importance of efficient and safe treatment of Crohns disease is highlighted by its chronicity. Both medical and surgical treatments have shown good results in the symptomatic control of limited ileocaecal Crohns disease. The aim of this study was to compare medical treatment with surgical treatment of ileocaecal Crohns disease. Methods: Thirty-six patients from seven hospitals with primary ileocaecal Crohns disease were randomized to either medical or surgical treatment. The medical treatment was induction of remission with budesonide and thereafter maintenance treatment with azathioprine. The surgical treatment was open ileocaecal resection. Crohns disease activity index over time, expressed as area under the curve at 1, 3 and 5 years, was the primary endpoint. Subjective health measured with the 36-item Short Form Survey Instrument (SF36) and a visual analogue scale (VAS) were secondary endpoints. Results: There were no differences between the treatment groups in Crohns disease activity index over time. General health, measured as SF36 score, was higher in patients receiving surgical treatment than in those receiving medical treatment at 1 year, but there was no corresponding difference in VAS. Due to the slow inclusion rate and changes in clinical practice, the study was t = erminated prematurely. Conclusion: The study ended up being underpowered and should be interpreted with caution, but there was no clinically significant difference between the two treatment arms. Further studies are needed to address this important clinical question.
|
|
| 6. |
|
|
| 7. |
- Johnson, Linda S, et al.
(författare)
-
Serum Potassium Is Positively Associated With Stroke and Mortality in the Large, Population-Based Malmö Preventive Project Cohort
- 2017
-
Ingår i: Stroke. - 1524-4628. ; 48:11, s. 2973-2978
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND PURPOSE: Low serum potassium is associated with stroke in populations with cardiovascular disease, hypertension, and diabetes mellitus but has not been studied in a mainly healthy population. We aimed to study the relation between serum potassium and incident stroke and mortality in the Malmö Preventive Project, a large cohort with screening in early mid-life and follow-up >25 years.METHODS: Serum potassium measurements and covariates were available in 21 353 individuals (79% men, mean age 44 years). Mean follow-up time was 26.9 years for stroke analyses and 29.3 years for mortality analyses. There were 2061 incident stroke events and 8709 deaths. Cox regression analyses adjusted for multiple stroke risk factors (age, sex, height, weight, systolic blood pressure, fasting blood glucose, serum sodium, current smoking, prevalent diabetes mellitus, prevalent coronary artery disease, and treatment for hypertension) were fitted.RESULTS: There was an independent, linear association between serum potassium, per mmol/L increase, and both stroke (hazard ratio, 1.33; 95% confidence interval, 1.17-1.52; P<0.0001) and mortality (hazard ratio, 1.20; 95% confidence interval, 1.13-1.28; P<0.0001). This was significant in subjects both older and younger than the median age (46.5 years), and there was evidence of an interaction with serum sodium. The association was positive and significant for both ischemic stroke and intracerebral hemorrhage and in both hypertensive and normotensive subjects.CONCLUSIONS: Serum potassium, measured in early mid-life, was linearly associated with both incidence of ischemic stroke and intracerebral hemorrhage and all-cause mortality. An interaction with serum sodium implies that factors related to electrolyte balance and incident hypertension may be mediating factors.
|
|
| 8. |
- Lagging, Cecilia, et al.
(författare)
-
APOE ε4 is associated with younger age at ischemic stroke onset but not with stroke outcome
- 2019
-
Ingår i: Neurology. - 1526-632X. ; 93:19, s. 849-853
-
Tidskriftsartikel (refereegranskat)abstract
- Stroke outcome is determined by a complex interplay, where age and stroke severity are predominant predictors. Studies on hemorrhagic stroke indicate that APOE genotype is a predictor of poststroke outcomes,1,2 but results from studies on ischemic stroke are more conflicting.1,3 There is 1 study suggesting an influence of APOE genotype on age at ischemic stroke onset,4 and sex-specific effects on outcome have been reported.5 Taken together, there is a need for larger studies on APOE and ischemic stroke outcomes with integrated information on age, severity, and sex.The 3 common APOE alleles ε2, ε3, and ε4 can be separated by a combination of 2 single nucleotide polymorphisms (SNPs), rs429358 and rs7412. Thus, associations with APOE alleles are not directly captured in a regular genome-wide association study (GWAS), where each SNP is investigated separately. We derived the 3 common APOE alleles and investigated the interplay between APOE, age at ischemic stroke onset, severity, sex, and outcome within a large international collaboration, the Genetics of Ischaemic Stroke Functional Outcome (GISCOME) network.
|
|
| 9. |
- Newton, Matilda S., et al.
(författare)
-
Structural and functional innovations in the real-time evolution of new (beta alpha)(8) barrel enzymes
- 2017
-
Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : NATL ACAD SCIENCES. - 0027-8424 .- 1091-6490. ; 114:18, s. 4727-4732
-
Tidskriftsartikel (refereegranskat)abstract
- New genes can arise by duplication and divergence, but there is a fundamental gap in our understanding of the relationship between these genes, the evolving proteins they encode, and the fitness of the organism. Here we used crystallography, NMR dynamics, kinetics, and mass spectrometry to explain the molecular innovations that arose during a previous real-time evolution experiment. In that experiment, the (beta alpha)(8) barrel enzyme HisA was under selection for two functions (HisA and TrpF), resulting in duplication and divergence of the hisA gene to encode TrpF specialists, HisA specialists, and bifunctional generalists. We found that selection affects enzyme structure and dynamics, and thus substrate preference, simultaneously and sequentially. Bifunctionality is associated with two distinct sets of loop conformations, each essential for one function. We observed two mechanisms for functional specialization: structural stabilization of each loop conformation and substrate-specific adaptation of the active site. Intracellular enzyme performance, calculated as the product of catalytic efficiency and relative expression level, was not linearly related to fitness. Instead, we observed thresholds for each activity above which further improvements in catalytic efficiency had little if any effect on growth rate. Overall, we have shown how beneficial substitutions selected during real-time evolution can lead to manifold changes in enzyme function and bacterial fitness. This work emphasizes the speed at which adaptive evolution can yield enzymes with sufficiently high activities such that they no longer limit the growth of their host organism, and confirms the (beta alpha)(8) barrel as an inherently evolvable protein scaffold.
|
|
| 10. |
- Newton, Matilda S., et al.
(författare)
-
Structural and functional innovations in the real-time evolution of new (βα)8 barrel enzymes
- 2017
-
Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 114:8, s. 4727-4732
-
Tidskriftsartikel (refereegranskat)abstract
- New genes can arise by duplication and divergence, but there is a fundamental gap in our understanding of the relationship between these genes, the evolving proteins they encode, and the fitness of the organism. Here we used crystallography, NMR dynamics, kinetics, and mass spectrometry to explain the molecular innovations that arose during a previous real-time evolution experiment. In that experiment, the (βα)8 barrel enzyme HisA was under selection for two functions (HisA and TrpF), resulting in duplication and divergence of the hisA gene to encode TrpF specialists, HisA specialists, and bifunctional generalists. We found that selection affects enzyme structure and dynamics, and thus substrate preference, simultaneously and sequentially. Bifunctionality is associated with two distinct sets of loop conformations, each essential for one function. We observed two mechanisms for functional specialization: structural stabilization of each loop conformation and substrate-specific adaptation of the active site. Intracellular enzyme performance, calculated as the product of catalytic efficiency and relative expression level, was not linearly related to fitness. Instead, we observed thresholds for each activity above which further improvements in catalytic efficiency had little if any effect on growth rate. Overall, we have shown how beneficial substitutions selected during real-time evolution can lead to manifold changes in enzyme function and bacterial fitness. This work emphasizes the speed at which adaptive evolution can yield enzymes with sufficiently high activities such that they no longer limit the growth of their host organism, and confirms the (βα)8 barrel as an inherently evolvable protein scaffold.
|
|
