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Sökning: WFRF:(Stanne Tara)

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1.
  • Andersson, Fredrik, 1977, et al. (författare)
  • Structure and function of a novel type of ATP-dependent Clp protease.
  • 2009
  • Ingår i: The Journal of biological chemistry. - 0021-9258 .- 1083-351X. ; 284:20, s. 13519-32
  • Tidskriftsartikel (refereegranskat)abstract
    • The Clp protease is conserved among eubacteria and most eukaryotes, and uses ATP to drive protein substrate unfolding and translocation into a chamber of sequestered proteolytic active sites. The main constitutive Clp protease in photosynthetic organisms has evolved into a functionally essential and structurally intricate enzyme. The model Clp protease from the cyanobacterium Synechococcus consists of the HSP100 molecular chaperone ClpC and a mixed proteolytic core comprised of two distinct subunits, ClpP3 and ClpR. We have purified the ClpP3/R complex, the first for a Clp proteolytic core comprised of heterologous subunits. The ClpP3/R complex has unique functional and structural features, consisting of twin heptameric rings each with an identical ClpP3(3)ClpR(4) configuration. As predicted by its lack of an obvious catalytic triad, the ClpR subunit is shown to be proteolytically inactive. Interestingly, extensive modification to ClpR to restore proteolytic activity to this subunit showed that its presence in the core complex is not rate-limiting for the overall proteolytic activity of the ClpCP3/R protease. Altogether, the ClpP3/R complex shows remarkable similarities to the 20 S core of the proteasome, revealing a far greater degree of convergent evolution than previously thought between the development of the Clp protease in photosynthetic organisms and that of the eukaryotic 26 S proteasome.
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2.
  • Angerfors, Annelie, et al. (författare)
  • Proteomic profiling identifies novel inflammation-related plasma proteins associated with ischemic stroke outcome
  • 2023
  • Ingår i: Journal of Neuroinflammation. - 1742-2094. ; 20:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Background The inflammatory response to cerebral ischemia is complex; however, most clinical studies of stroke outcome focus on a few selected proteins. We, therefore, aimed to profile a broad range of inflammation-related proteins to: identify proteins associated with ischemic stroke outcome that are independent of established clinical predictors; identify proteins subsets for outcome prediction; and perform sex and etiological subtype stratified analyses.Methods Acute-phase plasma levels of 65 inflammation-related proteins were measured in 534 ischemic stroke cases. Logistic regression was used to estimate associations to unfavorable 3-month functional outcome (modified Rankin Scale score > 2) and LASSO regressions to identify proteins with independent effects.Results Twenty proteins were associated with outcome in univariable models after correction for multiple testing (FDR < 0.05), and for 5 the association was independent of clinical variables, including stroke severity (TNFSF14 [LIGHT], OSM, SIRT2, STAMBP, and 4E-BP1). LASSO identified 9 proteins that could best separate favorable and unfavorable outcome with a predicted diagnostic accuracy (AUC) of 0.81; three associated with favorable (CCL25, TRAIL [TNFSF10], and Flt3L) and 6 with unfavorable outcome (CSF-1, EN-RAGE [S100A12], HGF, IL-6, OSM, and TNFSF14). Finally, we identified sex- and etiologic subtype-specific associations with the best discriminative ability achieved for cardioembolic, followed by cryptogenic stroke.Conclusions We identified candidate blood-based protein biomarkers for post-stroke functional outcome involved in, e.g., NLRP3 inflammasome regulation and signaling pathways, such as TNF, JAK/STAT, MAPK, and NF-kappa B. These proteins warrant further study for stroke outcome prediction as well as investigations into the putative causal role for stroke outcome.
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3.
  • Bonkhoff, A. K., et al. (författare)
  • Deep profiling of multiple ischemic lesions in a large, multi-center cohort: Frequency, spatial distribution, and associations to clinical characteristics
  • 2022
  • Ingår i: Frontiers in Neuroscience. - : Frontiers Media SA. - 1662-453X .- 1662-4548. ; 16
  • Tidskriftsartikel (refereegranskat)abstract
    • Background purposeA substantial number of patients with acute ischemic stroke (AIS) experience multiple acute lesions (MAL). We here aimed to scrutinize MAL in a large radiologically deep-phenotyped cohort. Materials and methodsAnalyses relied upon imaging and clinical data from the international MRI-GENIE study. Imaging data comprised both Fluid-attenuated inversion recovery (FLAIR) for white matter hyperintensity (WMH) burden estimation and diffusion-weighted imaging (DWI) sequences for the assessment of acute stroke lesions. The initial step featured the systematic evaluation of occurrences of MAL within one and several vascular supply territories. Associations between MAL and important imaging and clinical characteristics were subsequently determined. The interaction effect between single and multiple lesion status and lesion volume was estimated by means of Bayesian hierarchical regression modeling for both stroke severity and functional outcome. ResultsWe analyzed 2,466 patients (age = 63.4 +/- 14.8, 39% women), 49.7% of which presented with a single lesion. Another 37.4% experienced MAL in a single vascular territory, while 12.9% featured lesions in multiple vascular territories. Within most territories, MAL occurred as frequently as single lesions (ratio similar to 1:1). Only the brainstem region comprised fewer patients with MAL (ratio 1:4). Patients with MAL presented with a significantly higher lesion volume and acute NIHSS (7.7 vs. 1.7 ml and 4 vs. 3, p(FDR) < 0.001). In contrast, patients with a single lesion were characterized by a significantly higher WMH burden (6.1 vs. 5.3 ml, p(FDR) = 0.048). Functional outcome did not differ significantly between patients with single versus multiple lesions. Bayesian analyses suggested that the association between lesion volume and stroke severity between single and multiple lesions was the same in case of anterior circulation stroke. In case of posterior circulation stroke, lesion volume was linked to a higher NIHSS only among those with MAL. ConclusionMultiple lesions, especially those within one vascular territory, occurred more frequently than previously reported. Overall, multiple lesions were distinctly linked to a higher acute stroke severity, a higher total DWI lesion volume and a lower WMH lesion volume. In posterior circulation stroke, lesion volume was linked to a higher stroke severity in multiple lesions only.
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4.
  • Bonkhoff, A. K., et al. (författare)
  • Outcome after acute ischemic stroke is linked to sex-specific lesion patterns
  • 2021
  • Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 12:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Acute ischemic stroke affects men and women differently. In particular, women are often reported to experience higher acute stroke severity than men. We derived a low-dimensional representation of anatomical stroke lesions and designed a Bayesian hierarchical modeling framework tailored to estimate possible sex differences in lesion patterns linked to acute stroke severity (National Institute of Health Stroke Scale). This framework was developed in 555 patients (38% female). Findings were validated in an independent cohort (n=503, 41% female). Here, we show brain lesions in regions subserving motor and language functions help explain stroke severity in both men and women, however more widespread lesion patterns are relevant in female patients. Higher stroke severity in women, but not men, is associated with left hemisphere lesions in the vicinity of the posterior circulation. Our results suggest there are sex-specific functional cerebral asymmetries that may be important for future investigations of sex-stratified approaches to management of acute ischemic stroke.
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5.
  • Bonkhoff, A. K., et al. (författare)
  • Sex-specific lesion pattern of functional outcomes after stroke
  • 2022
  • Ingår i: Brain Communications. - : Oxford University Press (OUP). - 2632-1297. ; 4:2
  • Tidskriftsartikel (refereegranskat)abstract
    • Relying on neuroimaging and clinical data of 822 acute stroke patients, Bonkhoff et al. report substantially more detrimental effects of lesions in left-hemispheric posterior circulation regions on functional outcomes in women compared to men. These findings may motivate a sex-specific clinical stroke management to improve outcomes in the longer term. Stroke represents a considerable burden of disease for both men and women. However, a growing body of literature suggests clinically relevant sex differences in the underlying causes, presentations and outcomes of acute ischaemic stroke. In a recent study, we reported sex divergences in lesion topographies: specific to women, acute stroke severity was linked to lesions in the left-hemispheric posterior circulation. We here determined whether these sex-specific brain manifestations also affect long-term outcomes. We relied on 822 acute ischaemic patients [age: 64.7 (15.0) years, 39% women] originating from the multi-centre MRI-GENIE study to model unfavourable outcomes (modified Rankin Scale >2) based on acute neuroimaging data in a Bayesian hierarchical framework. Lesions encompassing bilateral subcortical nuclei and left-lateralized regions in proximity to the insula explained outcomes across men and women (area under the curve = 0.81). A pattern of left-hemispheric posterior circulation brain regions, combining left hippocampus, precuneus, fusiform and lingual gyrus, occipital pole and latero-occipital cortex, showed a substantially higher relevance in explaining functional outcomes in women compared to men [mean difference of Bayesian posterior distributions (men - women) = -0.295 (90% highest posterior density interval = -0.556 to -0.068)]. Once validated in prospective studies, our findings may motivate a sex-specific approach to clinical stroke management and hold the promise of enhancing outcomes on a population level.
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6.
  • Bonkhoff, Anna K, et al. (författare)
  • The relevance of rich club regions for functional outcome post-stroke is enhanced in women.
  • 2023
  • Ingår i: Human brain mapping. - : Wiley. - 1097-0193 .- 1065-9471. ; 44:4, s. 1579-1592
  • Tidskriftsartikel (refereegranskat)abstract
    • This study aimed to investigate the influence of stroke lesions in predefined highly interconnected (rich-club) brain regions on functional outcome post-stroke, determine their spatial specificity and explore the effects of biological sex on their relevance. We analyzed MRI data recorded at index stroke and ~3-months modified Rankin Scale (mRS) data from patients with acute ischemic stroke enrolled in the multisite MRI-GENIE study. Spatially normalized structural stroke lesions were parcellated into 108 atlas-defined bilateral (sub)cortical brain regions. Unfavorable outcome (mRS>2) was modeled in a Bayesian logistic regression framework. Effects of individual brain regions were captured as two compound effects for (i) six bilateral rich club and (ii) all further non-rich club regions. In spatial specificity analyses, we randomized the split into "rich club" and "non-rich club" regions and compared the effect of the actual rich club regions to the distribution of effects from 1000 combinations of six random regions. In sex-specific analyses, we introduced an additional hierarchical level in our model structure to compare male and female-specific rich club effects. A total of 822 patients (age: 64.7[15.0], 39% women) were analyzed. Rich club regions had substantial relevance in explaining unfavorable functional outcome (mean of posterior distribution: 0.08, area under the curve: 0.8). In particular, the rich club-combination had a higher relevance than 98.4% of random constellations. Rich club regions were substantially more important in explaining long-term outcome in women than in men. All in all, lesions in rich club regions were associated with increased odds of unfavorable outcome. These effects were spatially specific and more pronounced in women.
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7.
  • Bretzner, M., et al. (författare)
  • MRI Radiomic Signature of White Matter Hyperintensities Is Associated With Clinical Phenotypes
  • 2021
  • Ingår i: Frontiers in Neuroscience. - : Frontiers Media SA. - 1662-4548 .- 1662-453X. ; 15
  • Tidskriftsartikel (refereegranskat)abstract
    • Objective: Neuroimaging measurements of brain structural integrity are thought to be surrogates for brain health, but precise assessments require dedicated advanced image acquisitions. By means of quantitatively describing conventional images, radiomic analyses hold potential for evaluating brain health. We sought to: (1) evaluate radiomics to assess brain structural integrity by predicting white matter hyperintensities burdens (WMH) and (2) uncover associations between predictive radiomic features and clinical phenotypes. Methods: We analyzed a multi-site cohort of 4,163 acute ischemic strokes (AIS) patients with T2-FLAIR MR images with total brain and WMH segmentations. Radiomic features were extracted from normal-appearing brain tissue (brain mask-WMH mask). Radiomics-based prediction of personalized WMH burden was done using ElasticNet linear regression. We built a radiomic signature of WMH with stable selected features predictive of WMH burden and then related this signature to clinical variables using canonical correlation analysis (CCA). Results: Radiomic features were predictive of WMH burden (R-2 = 0.855 +/- 0.011). Seven pairs of canonical variates (CV) significantly correlated the radiomics signature of WMH and clinical traits with respective canonical correlations of 0.81, 0.65, 0.42, 0.24, 0.20, 0.15, and 0.15 (FDR-corrected p-values(CV1-6) < 0.001, p-value(CV7) = 0.012). The clinical CV1 was mainly influenced by age, CV2 by sex, CV3 by history of smoking and diabetes, CV4 by hypertension, CV5 by atrial fibrillation (AF) and diabetes, CV6 by coronary artery disease (CAD), and CV7 by CAD and diabetes. Conclusion: Radiomics extracted from T2-FLAIR images of AIS patients capture microstructural damage of the cerebral parenchyma and correlate with clinical phenotypes, suggesting different radiographical textural abnormalities per cardiovascular risk profile. Further research could evaluate radiomics to predict the progression of WMH and for the follow-up of stroke patients' brain health.
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8.
  • Bretzner, Martin, et al. (författare)
  • Radiomics-Derived Brain Age Predicts Functional Outcome After Acute Ischemic Stroke.
  • 2023
  • Ingår i: Neurology. - 1526-632X .- 0028-3878. ; 100:8
  • Tidskriftsartikel (refereegranskat)abstract
    • While chronological age is one of the most influential determinants of poststroke outcomes, little is known of the impact of neuroimaging-derived biological "brain age." We hypothesized that radiomics analyses of T2-FLAIR images texture would provide brain age estimates and that advanced brain age of patients with stroke will be associated with cardiovascular risk factors and worse functional outcomes.We extracted radiomics from T2-FLAIR images acquired during acute stroke clinical evaluation. Brain age was determined from brain parenchyma radiomics using an ElasticNet linear regression model. Subsequently, relative brain age (RBA), which expresses brain age in comparison with chronological age-matched peers, was estimated. Finally, we built a linear regression model of RBA using clinical cardiovascular characteristics as inputs and a logistic regression model of favorable functional outcomes taking RBA as input.We reviewed 4,163 patients from a large multisite ischemic stroke cohort (mean age = 62.8 years, 42.0% female patients). T2-FLAIR radiomics predicted chronological ages (mean absolute error = 6.9 years, r = 0.81). After adjustment for covariates, RBA was higher and therefore described older-appearing brains in patients with hypertension, diabetes mellitus, a history of smoking, and a history of a prior stroke. In multivariate analyses, age, RBA, NIHSS, and a history of prior stroke were all significantly associated with functional outcome (respective adjusted odds ratios: 0.58, 0.76, 0.48, 0.55; all p-values < 0.001). Moreover, the negative effect of RBA on outcome was especially pronounced in minor strokes.T2-FLAIR radiomics can be used to predict brain age and derive RBA. Older-appearing brains, characterized by a higher RBA, reflect cardiovascular risk factor accumulation and are linked to worse outcomes after stroke.
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9.
  • Brännmark, Cecilia, et al. (författare)
  • FIND Stroke Recovery Study (FIND): rationale and protocol for a longitudinal observational cohort study of trajectories of recovery and biomarkers poststroke
  • 2023
  • Ingår i: Bmj Open. - 2044-6055. ; 13:5
  • Tidskriftsartikel (refereegranskat)abstract
    • ntroduction Comprehensive studies mapping domain-specific trajectories of recovery after stroke and biomarkers reflecting these processes are scarce. We, therefore, initiated an exploratory prospective observational study of stroke cases with repeated evaluation, the FIND Stroke Recovery Study. We aim to capture trajectories of recovery from different impairments, including cognition, in combination with broad profiling of blood and imaging biomarkers of the recovery. Methods and analysis We recruit individuals with first-ever stroke at the stroke unit at the Sahlgrenska University Hospital, Sweden, to FIND. The inclusion started early 2018 and we aim to enrol minimum 500 patients. Neurological and cognitive impairments across multiple domains are assessed using validated clinical assessment methods, advanced neuroimaging is performed and blood samples for biomarker measuring (protein, RNA and DNA) at inclusion and follow-up visits at 3 months, 6 months, 1 year, 2 years and 5 years poststroke. At baseline and at each follow-up visit, we also register clinical variables known to influence outcomes such as prestroke functioning, stroke severity, acute interventions, rehabilitation, other treatments, socioeconomic status, infections (including COVID-19) and other comorbidities. Recurrent stroke and other major vascular events are identified continuously in national registers. Ethics and dissemination FIND composes a unique stroke cohort with detailed phenotyping, repetitive assessments of outcomes across multiple neurological and cognitive domains and patient-reported outcomes as well as blood and imaging biomarker profiling. Ethical approval for the FIND study has been obtained from the Regional Ethics Review Board in Gothenburg and the Swedish Ethics Review Board. The results of this exploratory study will provide novel data on the time course of recovery and biomarkers after stroke. The description of this protocol will inform the stroke research community of our ongoing study and facilitate comparisons with other data sets.
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10.
  • Cheng, Yu-Ching, et al. (författare)
  • Genome-Wide Association Analysis of Young-Onset Stroke Identifies a Locus on Chromosome 10q25 Near HABP2.
  • 2016
  • Ingår i: Stroke; a journal of cerebral circulation. - 1524-4628. ; 47:2, s. 307-16
  • Tidskriftsartikel (refereegranskat)abstract
    • Although a genetic contribution to ischemic stroke is well recognized, only a handful of stroke loci have been identified by large-scale genetic association studies to date. Hypothesizing that genetic effects might be stronger for early- versus late-onset stroke, we conducted a 2-stage meta-analysis of genome-wide association studies, focusing on stroke cases with an age of onset <60 years.
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11.
  • Cole, John W, et al. (författare)
  • Genetics of the thrombomodulin-endothelial cell protein C receptor system and the risk of early-onset ischemic stroke.
  • 2018
  • Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 13:11
  • Tidskriftsartikel (refereegranskat)abstract
    • Polymorphisms in coagulation genes have been associated with early-onset ischemic stroke. Here we pursue an a priori hypothesis that genetic variation in the endothelial-based receptors of the thrombomodulin-protein C system (THBD and PROCR) may similarly be associated with early-onset ischemic stroke. We explored this hypothesis utilizing a multi-stage design of discovery and replication.Discovery was performed in the Genetics-of-Early-Onset Stroke (GEOS) Study, a biracial population-based case-control study of ischemic stroke among men and women aged 15-49 including 829 cases of first ischemic stroke (42.2% African-American) and 850 age-comparable stroke-free controls (38.1% African-American). Twenty-four single-nucleotide-polymorphisms (SNPs) in THBD and 22 SNPs in PROCR were evaluated. Following LD pruning (r2≥0.8), we advanced uncorrelated SNPs forward for association analyses. Associated SNPs were evaluated for replication in an early-onset ischemic stroke population (onset-age<60 years) consisting of 3676 cases and 21118 non-stroke controls from 6 case-control studies. Lastly, we determined if the replicated SNPs also associated with older-onset ischemic stroke in the METASTROKE data-base.Among GEOS Caucasians, PROCR rs9574, which was in strong LD with 8 other SNPs, and one additional independent SNP rs2069951, were significantly associated with ischemic stroke (rs9574, OR = 1.33, p = 0.003; rs2069951, OR = 1.80, p = 0.006) using an additive-model adjusting for age, gender and population-structure. Adjusting for risk factors did not change the associations; however, associations were strengthened among those without risk factors. PROCR rs9574 also associated with early-onset ischemic stroke in the replication sample (OR = 1.08, p = 0.015), but not older-onset stroke. There were no PROCR associations in African-Americans, nor were there any THBD associations in either ethnicity.PROCR polymorphisms are associated with early-onset ischemic stroke in Caucasians.
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12.
  • Dorvall, Malin, 1991, et al. (författare)
  • Mosaic Loss of Chromosome Y Is Associated With Functional Outcome After Ischemic Stroke.
  • 2023
  • Ingår i: Stroke. - : Wolters Kluwer. - 1524-4628 .- 0039-2499. ; 54:9, s. 2434-2437
  • Tidskriftsartikel (refereegranskat)abstract
    • Mosaic loss of chromosome Y (LOY) is associated with cardiovascular and neurodegenerative diseases in men, and genetic predisposition to LOY is associated with poor poststroke outcome. We, therefore, tested the hypothesis that LOY itself is associated with functional outcome after ischemic stroke.The study comprised male patients with ischemic stroke from the cohort studies SAHLSIS2 (Sahlgrenska Academy Study on Ischemic Stroke Phase 2; n=588) and LSR (Lund Stroke Register; n=735). We used binary logistic regression to analyze associations between LOY, determined by DNA microarray intensity data, and poor 3-month functional outcome (modified Rankin Scale score, >2) in each cohort separately and combined. Patients who received recanalization therapy were excluded from sensitivity analyses.LOY was associated with about 2.5-fold increased risk of poor outcome in univariable analyses (P<0.001). This association withstood separate adjustment for stroke severity and diabetes in both cohorts but not age. In sensitivity analyses restricted to the nonrecanalization group (n=987 in the combined cohort), the association was significant also after separate adjustment for age (odds ratio, 1.6 [95% CI, 1.1-2.4]) and when additionally adjusting for stroke severity and diabetes (odds ratio, 1.6 [95% CI, 1.1-2.5]).We observed an association between LOY and poor outcome after ischemic stroke in patients not receiving recanalization therapy. Future studies on LOY and other somatic genetic alterations in larger stroke cohorts are warranted.
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13.
  • Holmegaard, Lukas, et al. (författare)
  • Proinflammatory protein signatures in cryptogenic and large artery atherosclerosis stroke
  • 2021
  • Ingår i: Acta neurologica Scandinavica. - : Hindawi Limited. - 1600-0404 .- 0001-6314. ; 143:3, s. 303-312
  • Tidskriftsartikel (refereegranskat)abstract
    • The cause of ischemic stroke remains unknown, cryptogenic, in 25% of young and middle-aged patients. We hypothesized that if atherosclerosis is prominent in cryptogenic stroke, it would have a similar proinflammatory protein signature as large artery atherosclerosis (LAA) stroke.Blood was collected in the acute phase and after 3months from cryptogenic (n=162) and LAA (n=73) stroke patients aged 18-69years and once from age-matched controls (n=235). Cryptogenic stroke was divided into Framingham Risk Score (FRS) quartiles to compare low and high risk of atherosclerosis. Plasma concentrations of 25 proteins were analyzed using a Luminex multiplex assay. The discriminating properties were assessed with discriminant analysis and C-statistics.We identified proteins that separated cryptogenic and LAA stroke from controls (area under the curves, AUCs≥0.85). For both subtypes, RANTES, IL-4, and IFN-γ contributed the most at both time points. These associations were independent of risk factors of atherosclerosis. We also identified proteins that separated cryptogenic strokes in the lowest quartile of FRS from those in the highest, and from LAA stroke (AUCs≥0.76), and here eotaxin and MCP-1 contributed the most.The protein signature separating cases from controls was different from the signature separating cryptogenic stroke with low risk of atherosclerosis from those with high risk and from LAA stroke. This suggests that increased RANTES, IL-4, and IFN-γ in stroke may not be primarily related to atherosclerosis, whereas increased eotaxin and MCP-1 in cryptogenic stroke may be markers of occult atherosclerosis as the underlying cause.
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14.
  • Jaworek, T., et al. (författare)
  • Contribution of Common Genetic Variants to Risk of Early-Onset Ischemic Stroke
  • 2022
  • Ingår i: Neurology. - : Ovid Technologies (Wolters Kluwer Health). - 0028-3878 .- 1526-632X. ; 99:16
  • Tidskriftsartikel (refereegranskat)abstract
    • Background and Objectives Current genome-wide association studies of ischemic stroke have focused primarily on late-onset disease. As a complement to these studies, we sought to identify the contribution of common genetic variants to risk of early-onset ischemic stroke. Methods We performed a meta-analysis of genome-wide association studies of early-onset stroke (EOS), ages 18-59 years, using individual-level data or summary statistics in 16,730 cases and 599,237 nonstroke controls obtained across 48 different studies. We further compared effect sizes at associated loci between EOS and late-onset stroke (LOS) and compared polygenic risk scores (PRS) for venous thromboembolism (VTE) between EOS and LOS. Results We observed genome-wide significant associations of EOS with 2 variants in ABO, a known stroke locus. These variants tag blood subgroups O1 and A1, and the effect sizes of both variants were significantly larger in EOS compared with LOS. The odds ratio (OR) for rs529565, tagging O1, was 0.88 (95% confidence interval [CI]: 0.85-0.91) in EOS vs 0.96 (95% CI: 0.92-1.00) in LOS, and the OR for rs635634, tagging A1, was 1.16 (1.11-1.21) for EOS vs 1.05 (0.99-1.11) in LOS; p-values for interaction = 0.001 and 0.005, respectively. Using PRSs, we observed that greater genetic risk for VTE, another prothrombotic condition, was more strongly associated with EOS compared with LOS (p = 0.008). Discussion The ABO locus, genetically predicted blood group A, and higher genetic propensity for venous thrombosis are more strongly associated with EOS than with LOS, supporting a stronger role of prothrombotic factors in EOS.
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15.
  • Johansson, Malin, et al. (författare)
  • Genetic Predisposition to Mosaic Chromosomal Loss Is Associated with Functional Outcome after Ischemic Stroke
  • 2021
  • Ingår i: Neurology: Genetics. - 2376-7839. ; 7:6
  • Tidskriftsartikel (refereegranskat)abstract
    • Background and ObjectivesTo test the hypothesis that a predisposition to acquired genetic alterations is associated with ischemic stroke outcome by investigating the association between a polygenic risk score (PRS) for mosaic loss of chromosome Y (mLOY) and outcome in a large international data set.MethodsWe used data from the genome-wide association study performed within the Genetics of Ischemic Stroke Functional Outcome network, which included 6,165 patients (3,497 men and 2,668 women) with acute ischemic stroke of mainly European ancestry. We assessed a weighted PRS for mLOY and examined possible associations with the modified Rankin Scale (mRS) score 3 months poststroke in logistic regression models. We investigated the whole study sample as well as men and women separately.ResultsIncreasing PRS for mLOY was associated with poor functional outcome (mRS score >2) with an odds ratio (OR) of 1.11 (95% confidence interval [CI] 1.03-1.19) per 1 SD increase in the PRS after adjustment for age, sex, ancestry, stroke severity (NIH Stroke Scale), smoking, and diabetes mellitus. In sex-stratified analyses, we found a statistically significant association in women (adjusted OR 1.20, 95% CI 1.08-1.33). In men, the association was in the same direction (adjusted OR 1.04, 95% CI 0.95-1.14), and we observed no significant genotype-sex interaction.DiscussionIn this exploratory study, we found associations between genetic variants predisposing to mLOY and stroke outcome. The significant association in women suggests underlying mechanisms related to genomic instability that operate in both sexes. These findings need replication and mechanistic exploration.
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16.
  • Koussevitzky, S., et al. (författare)
  • An Arabidopsis thaliana virescent mutant reveals a role for ClpR1 in plastid development
  • 2007
  • Ingår i: Plant Molecular Biology. - : Springer Science and Business Media LLC. - 0167-4412 .- 1573-5028. ; 63:1, s. 85-96
  • Tidskriftsartikel (refereegranskat)abstract
    • The ATP-dependent Clp protease has been well-characterized in Escherichia coli, but knowledge of its function in higher plants is limited. In bacteria, this two-component protease consists of a Ser-type endopeptidase ClpP, which relies on the ATP-dependent unfolding activity from an Hsp100 molecular chaperone to initiate protein degradation. In the chloroplasts of higher plants, multiple isoforms of the proteolytic subunit exist, with Arabidopsis having five ClpPs and four ClpP-like proteins termed ClpR predicted in its genome. In this work we characterized an Arabidopsis mutant impaired in one subunit of the chloroplast-localized Clp protease core, ClpR1. clpR1-1, a virescent mutant, carries a pre-mature stop codon in the clpR1 gene, resulting in no detectable ClpR1 protein. The accumulation of several chloroplast proteins, as well as most of the chloroplast-localized Clp protease subunits, is inhibited in clpR1-1. Unexpectedly, some plastid-encoded proteins do not accumulate, although their transcripts accumulate to wild-type levels. Maturation of 23S and 4.5S chloroplast ribosomal RNA (cp-rRNA) is delayed in clpR1-1, and both RNAs accumulate as higher molecular weight precursors. Also, chloroplasts in clpR1-1 are smaller than in wild type and have fewer thylakoid membranes with smaller grana stacks. We propose that a ClpR1-containing activity is required for chloroplast development and differentiation and in its absence both are delayed.
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17.
  • 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.
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18.
  • Lagging, Cecilia, et al. (författare)
  • Investigation of 91 proteins implicated in neurobiological processes identifies multiple candidate plasma biomarkers of stroke outcome
  • 2022
  • Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322 .- 2045-2322. ; 12:1
  • Tidskriftsartikel (refereegranskat)abstract
    • The inter-individual variation in stroke outcomes is large and protein studies could point to potential underlying biological mechanisms. We measured plasma levels of 91 neurobiological proteins in 209 cases included in the Sahlgrenska Academy Study on Ischemic Stroke using a Proximity Extension Assay, and blood was sampled in the acute phase and at 3-month and 7-year follow-ups. Levels were also determined once in 209 controls. Acute stroke severity and neurological outcome were evaluated by the National Institutes of Health Stroke Scale. In linear regression models corrected for age, sex, and sampling day, acute phase levels of 37 proteins were associated with acute stroke severity, and 47 with 3-month and/or 7-year outcome at false discovery rate < 0.05. Three-month levels of 8 proteins were associated with 7-year outcome, of which the associations for BCAN and Nr-CAM were independent also of acute stroke severity. Most proteins followed a trajectory with lower levels in the acute phase compared to the 3-month follow-up and the control sampling point. Conclusively, we identified multiple candidate plasma biomarkers of stroke severity and neurological outcome meriting further investigation. This study adds novel information, as most of the reported proteins have not been previously investigated in a stroke cohort.
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19.
  • Maguire, Jane M., et al. (författare)
  • GISCOME – Genetics of Ischaemic Stroke Functional Outcome network : A protocol for an international multicentre genetic association study
  • 2017
  • Ingår i: European Stroke Journal. - : SAGE Publications. - 2396-9873 .- 2396-9881. ; 2:3, s. 229-237
  • Tidskriftsartikel (refereegranskat)abstract
    • Introduction: Genome-wide association studies have identified several novel genetic loci associated with stroke risk, but how genetic factors influence stroke outcome is less studied. The Genetics of Ischaemic Stroke Functional outcome network aims at performing genetic studies of stroke outcome. We here describe the study protocol and methods basis of Genetics of Ischaemic Stroke Functional outcome. Methods: The Genetics of Ischaemic Stroke Functional outcome network has assembled patients from 12 ischaemic stroke projects with genome-wide genotypic and outcome data from the International Stroke Genetics Consortium and the National Institute of Neurological Diseases Stroke Genetics Network initiatives. We have assessed the availability of baseline variables, outcome metrics and time-points for collection of outcome data. Results: We have collected 8831 ischaemic stroke cases with genotypic and outcome data. Modified Rankin score was the outcome metric most readily available. We detected heterogeneity between cohorts for age and initial stroke severity (according to the NIH Stroke Scale), and will take this into account in analyses. We intend to conduct a first phase genome-wide association outcome study on ischaemic stroke cases with data on initial stroke severity and modified Rankin score within 60–190 days. To date, we have assembled 5762 such cases and are currently seeking additional cases meeting these criteria for second phase analyses. Conclusion: Genetics of Ischaemic Stroke Functional outcome is a unique collection of ischaemic stroke cases with detailed genetic and outcome data providing an opportunity for discovery of genetic loci influencing functional outcome. Genetics of Ischaemic Stroke Functional outcome will serve as an exploratory study where the results as well as the methodological observations will provide a basis for future studies on functional outcome. Genetics of Ischaemic Stroke Functional outcome can also be used for candidate gene replication or assessing stroke outcome non-genetic association hypotheses.
  •  
20.
  • Mola-Caminal, M., et al. (författare)
  • PATJ Low Frequency Variants Are Associated With Worse Ischemic Stroke Functional Outcome A Genome-Wide Meta-Analysis
  • 2019
  • Ingår i: Circulation research. - : Ovid Technologies (Wolters Kluwer Health). - 0009-7330 .- 1524-4571. ; 124:1, s. 114-120
  • Tidskriftsartikel (refereegranskat)abstract
    • 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, beta=0.40, P=1.70x10-9). 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.
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21.
  • Olsson Lindvall, Martina, et al. (författare)
  • A Comprehensive Sequencing-Based Analysis of Allelic Methylation Patterns in Hemostatic Genes in Human Liver
  • 2020
  • Ingår i: Thrombosis and Haemostasis. - : Georg Thieme Verlag KG. - 0340-6245 .- 2567-689X. ; 120:2, s. 229-242
  • Tidskriftsartikel (refereegranskat)abstract
    • Characterizing the relationship between genetic, epigenetic (e.g., deoxyribonucleic acid [DNA] methylation), and transcript variation could provide insights into mechanisms regulating hemostasis and potentially identify new drug targets. Several hemostatic factors are synthesized in the liver, yet high-resolution DNA methylation data from human liver tissue is currently lacking for these genes. Single-nucleotide polymorphisms (SNPs) can influence DNA methylation in cis which can affect gene expression. This can be analyzed through allele-specific methylation (ASM) experiments. We performed targeted genomic DNA- and bisulfite-sequencing of 35 hemostatic genes in human liver samples for SNP and DNA methylation analysis, respectively, and integrated the data for ASM determination. ASM-associated SNPs (ASM-SNPs) were tested for association to gene expression in liver using in-house generated ribonucleic acid-sequencing data. We then assessed whether ASM-SNPs associated with gene expression, plasma proteins, or other traits relevant for hemostasis using publicly available data. We identified 112 candidate ASM-SNPs. Of these, 68% were associated with expression of their respective genes in human liver or in other human tissues and 54% were associated with the respective plasma protein levels, activity, or other relevant hemostatic genome-wide association study traits such as venous thromboembolism, coronary artery disease, stroke, and warfarin dose maintenance. Our study provides the first detailed map of the DNA methylation landscape and ASM analysis of hemostatic genes in human liver tissue, and suggests that methylation regulated by genetic variants in cis may provide a mechanistic link between noncoding SNPs and variation observed in circulating hemostatic proteins, prothrombotic diseases, and drug response.
  •  
22.
  • Olsson Lindvall, Martina, et al. (författare)
  • Comparison of DNA Methylation Profiles of Hemostatic Genes between Liver Tissue and Peripheral Blood within Individuals
  • 2021
  • Ingår i: Thrombosis and Haemostasis. - : Georg Thieme Verlag KG. - 0340-6245 .- 2567-689X. ; 121:5, s. 573-583
  • Tidskriftsartikel (refereegranskat)abstract
    • DNA methylation has become increasingly recognized in the etiology of complex diseases, including thrombotic disorders. Blood is often collected in epidemiological studies for genotyping and has recently also been used to examine DNA methylation in epigenome-wide association studies. DNA methylation patterns are often tissue-specific, thus, peripheral blood may not accurately reflect the methylation pattern in the tissue of relevance. Here, we collected paired liver and blood samples concurrently from 27 individuals undergoing liver surgery. We performed targeted bisulfite sequencing for a set of 35 hemostatic genes primarily expressed in liver to analyze DNA methylation levels of >10,000 cytosine-phosphate-guanine (CpG) dinucleotides. We evaluated whether DNA methylation in blood could serve as a proxy for DNA methylation in liver at individual CpGs. Approximately 30% of CpGs were nonvariable and were predominantly hypo- (<25%) or hypermethylated (>70%) in both tissues. While blood can serve as a proxy for liver at these CpGs, the low variability renders these unlikely to explain phenotypic differences. We therefore focused on CpG sites with variable methylation levels in liver. The level of blood-liver tissue correlation varied widely across these variable CpGs; moderate correlations (0.5 <= r <0.75) were detected for 6% and strong correlations ( r 0.75) for a further 4%. Our findings indicate that it is essential to study the concordance of DNA methylation between blood and liver at individual CpGs. This paired blood-liver dataset is intended as a resource to aid interpretation of blood-based DNA methylation results.
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23.
  • Olsson Lindvall, Martina, et al. (författare)
  • Hemostatic Genes Exhibit a High Degree of Allele-Specific Regulation in Liver
  • 2019
  • Ingår i: Thrombosis and Haemostasis. - : Georg Thieme Verlag KG. - 0340-6245 .- 2567-689X. ; 119:7, s. 1072-1083
  • Tidskriftsartikel (refereegranskat)abstract
    • Objective Elucidating the genetic basis underlying hepatic hemostatic gene expression variability may contribute to unraveling genetic factors contributing to thrombotic or bleeding disorders. We aimed to identify novel cis-regulatory variants involved in regulating hemostatic genes by analyzing allele-specific expression (ASE) in human liver samples. Study Design Biopsies of human liver tissue and blood were collected from adults undergoing liver surgery at the Sahlgrenska University Hospital (n =20). Genomic deoxyribonucleic acid (gDNA) and total ribonucleic acid (RNA) were isolated. A targeted approach was used to enrich and sequence 35 hemostatic genes for single nucleotide polymorphism (SNP) analysis (gDNAseq) and construct individualized genomes for transcript alignment. The allelic ratio of transcripts from targeted RNAseq was determined via ASE analysis. Public expression quantitative trait loci (eQTL) and genome-wide association study (GWAS) data were used to assess novelty and importance of the ASE SNPs (and proxies, r(2) >= 0.8) for relevant traits/diseases. Results Sixty percent of the genes studied showed allelic imbalance across 53 SNPs. Of these, 7 SNPs were previously validated in liver eQTL studies. For 32 with eQTLs in other cell/tissue types, this is the first time genotype-specific expression is demonstrated in liver, and for 14 ASE SNPs, this is the first ever reported genotype-expression association. A total of 29 ASE SNPs were previously associated with the respective plasma protein levels and 17 ASE SNPs to other relevant GWAS traits including venous thromboembolism, coronary artery disease, and stroke. Conclusion Our study provides a comprehensive ASE analysis of hemostatic genes and insights into the regulation of hemostatic genes in human liver.
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24.
  • Olsson, Maja, 1975, et al. (författare)
  • Genome-wide analysis of genetic determinants of circulating factorVII-activating protease (FSAP) activity
  • 2018
  • Ingår i: Journal of Thrombosis and Haemostasis. - : Elsevier BV. - 1538-7933 .- 1538-7836. ; 16:10, s. 2024-2034
  • Tidskriftsartikel (refereegranskat)abstract
    • Background FactorVII-activating protease (FSAP) has roles in both coagulation and fibrinolysis. Recent data indicate its involvement in several other processes, such as vascular remodeling and inflammation. Plasma FSAP activity is highly variable among healthy individuals and, apart from the low-frequency missense variant Marburg-I (rs7080536) in the FSAP-encoding gene HABP2, determinants of this variation are unclear. Objectives To identify novel genetic variants within and outside of the HABP2 locus that influence circulating FSAP activity. Patients/Methods We performed an exploratory genome-wide association study (GWAS) on plasma FSAP activity amongst 3230 Swedish subjects. Directly genotyped rare variants were also analyzed with gene-based tests. Using GWAS, we confirmed the strong association between the Marburg-I variant and FSAP activity. HABP2 was also significant in the gene-based analysis, and remained significant after exclusion of Marburg-I carriers. This was attributable to a rare HABP2 stop variant (rs41292628). Carriers of this stop variant showed a similar reduction in FSAP activity as Marburg-I carriers, and this finding was replicated. A secondary genome-wide significant locus was identified at a 5p15 locus (rs35510613), and this finding requires future replication. This common variant is located upstream of ADCY2, which encodes a protein catalyzing the formation of cAMP. Results and Conclusions This study verified the Marburg-I variant to be a strong regulator of FSAP activity, and identified an HABP2 stop variant with a similar impact on FSAP activity. A novel locus near ADCY2 was identified as a potential additional regulator of FSAP activity.
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25.
  • Pedersen, Annie, 1981, et al. (författare)
  • Circulating neurofilament light in ischemic stroke: temporal profile and outcome prediction
  • 2019
  • Ingår i: Journal of Neurology. - : Springer Science and Business Media LLC. - 0340-5354 .- 1432-1459. ; 266:11, s. 2796-2806
  • Tidskriftsartikel (refereegranskat)abstract
    • Background and purpose Neurofilament light chain (NfL) is a marker of neuroaxonal damage. We aimed to study associations between serum NfL (sNfL) concentrations at different time points after ischemic stroke and outcomes. Methods We prospectively included ischemic stroke cases (n=595, mean age 59 years, 64% males) and assessed outcomes by both the modified Rankin Scale (mRS) and the NIH stroke scale (NIHSS) at 3 months and by mRS at 2 years. In a subsample, long-term (7-year) outcomes were also assessed by both mRS and NIHSS. We used the ultrasensitive single-molecule array assay to measure sNfL in the acute phase (range 1–14, median 4 days), after 3 months and 7 years in cases and once in controls (n=595). Results Acute-phase sNfL increased by the time to blood-draw and highest concentrations were observed at 3 months post-stroke. High sNfL associated to stroke severity and poor outcomes, and both associations were strongest for 3-month sNfL. After adjusting for age, previous stroke, stroke severity, and day of blood draw, 3-month sNfL was significantly associated to both outcomes at all time points (p<0.01 throughout). For all main etiological subtypes, both acute phase and 3-month sNfL were significantly higher than in controls, but the dynamics of sNfL differed by stroke subtype. Conclusions The results from this study inform on sNfL in ischemic stroke and subtypes over time, and show that sNfL predicts short- and long-term neurological and functional outcomes. Our findings suggest a potential utility of sNfL in ischemic stroke outcome prediction.
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26.
  • Pedersen, Annie, 1981, et al. (författare)
  • Fibrinogen concentrations predict long-term cognitive outcome in young ischemic stroke patients
  • 2018
  • Ingår i: Research and Practice in Thrombosis and Haemostasis. - : Elsevier BV. - 2475-0379. ; 2:2, s. 339-346
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Cognitive impairment is frequent after stroke, and young patients may live with this consequence for a long time. Predictors of cognitive outcomes after stroke represent a current gap of knowledge. Objectives: To investigate levels of three hemostatic biomarkers as predictors of long-term cognitive function after stroke. Methods: This longitudinal study included consecutively recruited patients with ischemic stroke at 18-69 years (n = 268). Blood was collected 3 months after index stroke and analyzed for plasma concentrations of fibrinogen, von Willebrand factor (VWF) and tissue-type plasminogen activator (t-PA) antigen. Cognitive function 7 years after index stroke was assessed by the Barrow Neurological Institute Screen for Higher Cerebral Functions (BNIS). Participants with stroke <50 years of age were also examined by the Trail Making Test A and B (n = 41). Associations between biomarker concentrations and cognitive scales were assessed in the whole group and in participants with stroke <50 years of age. Results: The hemostatic biomarkers fibrinogen, VWF and t-PA, were all correlated to total BNIS score, but these associations did not withstand adjustment for confounding factors in the whole group. However, in patients <50 years, we found an independent association between fibrinogen concentrations and total BNIS score (beta(std) = -.27, 95% confidence interval [CI], -0.47 to -0.07) and to performance on the Trail Making Test A (beta(std) = 31, 95% CI, 0.03-0.58). No such association was seen for the Trail Making Test B. Conclusion: High convalescent fibrinogen concentrations were associated with worse long-term cognitive outcomes in ischemic stroke <50 years of age. We propose further investigations of fibrinogen in relation to cognitive function in stroke in the young.
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27.
  • Pedersen, Annie, 1981, et al. (författare)
  • TFPI gene variation and ischemic stroke.
  • 2012
  • Ingår i: Thrombosis research. - : Elsevier BV. - 1879-2472 .- 0049-3848. ; 130:3, s. 565-7
  • Tidskriftsartikel (refereegranskat)
  •  
28.
  • 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.
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29.
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30.
  • Sjögren, Lars, 1977, et al. (författare)
  • Structural and functional insights into the chloroplast ATP-dependent Clp protease in Arabidopsis
  • 2006
  • Ingår i: Plant Cell. - : Oxford University Press (OUP). - 1040-4651 .- 1532-298X. ; 18:10, s. 2635-2649
  • Tidskriftsartikel (refereegranskat)abstract
    • In contrast with the model Escherichia coli Clp protease, the ATP- dependent Clp protease in higher plants has a remarkably diverse proteolytic core consisting of multiple ClpP and ClpR paralogs, presumably arranged within a dual heptameric ring structure. Using antisense lines for the nucleus- encoded ClpP subunit, ClpP6, we show that the Arabidopsis thaliana Clp protease is vital for chloroplast development and function. Repression of ClpP6 produced a proportional decrease in the Clp proteolytic core, causing a chlorotic phenotype in young leaves that lessened upon maturity. Structural analysis of the proteolytic core revealed two distinct subcomplexes that likely correspond to single heptameric rings, one containing the ClpP1 and ClpR1- 4 proteins, the other containing ClpP3- 6. Proteomic analysis revealed several stromal proteins more abundant in clpP6 antisense lines, suggesting that some are substrates for the Clp protease. A proteolytic assay developed for intact chloroplasts identified potential substrates for the stromal Clp protease in higher plants, most of which were more abundant in young Arabidopsis leaves, consistent with the severity of the chlorotic phenotype observed in the clpP6 antisense lines. The identified substrates all function in more general housekeeping roles such as plastid protein synthesis, folding, and quality control, rather than in metabolic activities such as photosynthesis.
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31.
  • Soderholm, M., et al. (författare)
  • Genome-wide association meta-analysis of functional outcome after ischemic stroke
  • 2019
  • Ingår i: Neurology. - : Ovid Technologies (Wolters Kluwer Health). - 0028-3878 .- 1526-632X. ; 92:12
  • Tidskriftsartikel (refereegranskat)abstract
    • Objective To discover common genetic variants associated with poststroke outcomes using a genome-wide association (GWA) study. Methods The study comprised 6,165 patients with ischemic stroke from 12 studies in Europe, the United States, and Australia included in the GISCOME (Genetics of Ischaemic Stroke Functional Outcome) network. The primary outcome was modified Rankin Scale score after 60 to 190 days, evaluated as 2 dichotomous variables (0-2 vs 3-6 and 0-1 vs 2-6) and subsequently as an ordinal variable. GWA analyses were performed in each study independently and results were meta-analyzed. Analyses were adjusted for age, sex, stroke severity (baseline NIH Stroke Scale score), and ancestry. The significance level was p < 5 x 10(-8). Results We identified one genetic variant associated with functional outcome with genome-wide significance (modified Rankin Scale scores 0-2 vs 3-6, p = 5.3 x 10(-9)). This intronic variant (rs1842681) in the LOC105372028 gene is a previously reported trans-expression quantitative trait locus for PPP1R21, which encodes a regulatory subunit of protein phosphatase 1. This ubiquitous phosphatase is implicated in brain functions such as brain plasticity. Several variants detected in this study demonstrated suggestive association with outcome (p < 10(-5)), some of which are within or near genes with experimental evidence of influence on ischemic stroke volume and/or brain recovery (e.g., NTN4, TEK, and PTCH1). Conclusions In this large GWA study on functional outcome after ischemic stroke, we report one significant variant and several variants with suggestive association to outcome 3 months after stroke onset with plausible mechanistic links to poststroke recovery. Future replication studies and exploration of potential functional mechanisms for identified genetic variants are warranted.
  •  
32.
  • Stanne, Tara M, 1979, et al. (författare)
  • A Genome-wide Study of Common and Rare Genetic Variants Associated with Circulating Thrombin Activatable Fibrinolysis Inhibitor
  • 2018
  • Ingår i: Thrombosis and Haemostasis. - : Georg Thieme Verlag KG. - 0340-6245 .- 2567-689X. ; 118:2, s. 298-308
  • Tidskriftsartikel (refereegranskat)abstract
    • Thrombin-activatable fibrinolysis inhibitor (TAFI) plays a central role in haemostasis, and plasma TAFI concentrations are heritable. Candidate gene studies have identified several variants within the gene encoding TAFI, CPB2, that explain part of the estimated heritability. Here, we describe an exploratory genome-wide association study to identify novel variants within and outside of the CPB2 locus that influence plasma concentrations of intact TAFI and/or the extent of TAFI activation (measured by released TAFI activation peptide, TAFI-AP) amongst 3,260 subjects from Southern Sweden. We also explored the role of rare variants on the HumanExome BeadChip. We confirmed the association with previously reported common variants in CPB2 for both intact TAFI and TAFI-AP, and discovered novel associations with variants in putative CPB2 enhancers. We identified a gene-based association with intact TAFI at CPB2 (PSKAT-O = 2.8 x 10(-8)), driven by two novel rare nonsynonymous single nucleotide polymorphisms (SNPs; I420N and D177G). Carriers of the rare variant of D177G (rs140446990; MAF 0.2%) had lower intact TAFI and TAFI-AP concentrations compared with non-carriers (intact TAFI, geometricmean 53 vs. 78%, PT-test < 5 x 10(-7); TAFI-AP 63 vs. 99%, P(T-tes)t = 7.2 x 10(-4)). For TAFI-AP, we identified a genome-wide significant association at an intergenic region of chromosome 3p14.1 and five gene-based associations (all PSKAT-O = 5 x 10(-6)). Using well-characterized assays together with a genome-wide association study and a rare-variant approach, we verified CPB2 to be the primary determinant of TAFI concentrations and identified putative secondary loci (candidate variants and genes) associated with intact TAFI and TAFI-AP that require independent validation.
  •  
33.
  • Stanne, Tara M., et al. (författare)
  • A Genome-wide Study of Common and Rare Genetic Variants Associated with Circulating Thrombin Activatable Fibrinolysis Inhibitor
  • 2018
  • Ingår i: Thrombosis and Haemostasis. - 0340-6245. ; 118:2, s. 298-308
  • Tidskriftsartikel (refereegranskat)abstract
    • Thrombin-activatable fibrinolysis inhibitor (TAFI) plays a central role in haemostasis, and plasma TAFI concentrations are heritable. Candidate gene studies have identified several variants within the gene encoding TAFI, CPB2, that explain part of the estimated heritability. Here, we describe an exploratory genome-wide association study to identify novel variants within and outside of the CPB2 locus that influence plasma concentrations of intact TAFI and/or the extent of TAFI activation (measured by released TAFI activation peptide, TAFI-AP) amongst 3,260 subjects from Southern Sweden. We also explored the role of rare variants on the HumanExome BeadChip. We confirmed the association with previously reported common variants in CPB2 for both intact TAFI and TAFI-AP, and discovered novel associations with variants in putative CPB2 enhancers. We identified a gene-based association with intact TAFI at CPB2 (P SKAT-O = 2.8 × 10 -8), driven by two novel rare nonsynonymous single nucleotide polymorphisms (SNPs; I420N and D177G). Carriers of the rare variant of D177G (rs140446990; MAF 0.2%) had lower intact TAFI and TAFI-AP concentrations compared with non-carriers (intact TAFI, geometric mean 53 vs. 78%, P T-test = 5 × 10 -7; TAFI-AP 63 vs. 99%, P T-test = 7.2 × 10 -4). For TAFI-AP, we identified a genome-wide significant association at an intergenic region of chromosome 3p14.1 and five gene-based associations (all P SKAT-O < 5 × 10 -6). Using well-characterized assays together with a genome-wide association study and a rare-variant approach, we verified CPB2 to be the primary determinant of TAFI concentrations and identified putative secondary loci (candidate variants and genes) associated with intact TAFI and TAFI-AP that require independent validation.
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34.
  • Stanne, Tara M, 1979, et al. (författare)
  • Association of Plasma Brain-Derived Tau With Functional Outcome After Ischemic Stroke.
  • 2024
  • Ingår i: Neurology. - 1526-632X. ; 102:4
  • Tidskriftsartikel (refereegranskat)abstract
    • To investigate whether circulating acute-phase brain-derived tau (BD-tau) is associated with functional outcome after ischemic stroke.Plasma tau was measured by a novel assay that selectively quantifies BD-tau in the Sahlgrenska Academy Study on Ischemic Stroke (SAHLSIS), which includes adult cases with ischemic stroke and controls younger than 70 years, and in an independent cohort of adult cases of all ages (SAHLSIS2). Associations with unfavorable 3-month functional outcome (modified Rankin scale score >2) were analyzed by logistic regression. Various stratified and sensitivity analyses were performed, for example, by age, stroke severity, recanalization therapy, and etiologic subtype.This study included 454 and 364 cases from the SAHLSIS and SAHLSIS2, with a median age of 58 and 68 years, respectively. Higher acute BD-tau concentrations were significantly associated with increased odds of unfavorable outcome after adjustment for age, sex, day of blood draw, and stroke severity (NIH stroke scale score) in both cohorts (OR per doubling of BD-tau: 2.9 [95% CI 2.2-3.7], P = 1 × 10-15 and 1.8 [1.5-2.2], P = 7 × 10-9, respectively). The association was consistent in the different stratified and sensitivity analyses.BD-tau is a promising blood-based biomarker of ischemic stroke outcomes, and future studies in larger cohorts are warranted.
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35.
  • Stanne, Tara M, 1979, et al. (författare)
  • Distinctive types of ATP-dependent Clp proteases in cyanobacteria
  • 2007
  • Ingår i: Journal of Biological Chemistry. - 0021-9258. ; 282:19, s. 14394-14402
  • Tidskriftsartikel (refereegranskat)abstract
    • Cyanobacteria are the only prokaryotes that perform oxygenic photosynthesis and are thought to be ancestors to plant chloroplasts. Like chloroplasts, cyanobacteria possess a diverse array of proteolytic enzymes, with one of the most prominent being the ATP-dependent Ser-type Clp protease. The model Clp protease in Escherichia coli consists of a single ClpP proteolytic core flanked on one or both ends by a HSP100 chaperone partner. In comparison, cyanobacteria have multiple ClpP paralogs plus a ClpP variant (ClpR), which lacks the catalytic triad typical of Ser-type proteases. In this study, we reveal that two distinct soluble Clp proteases exist in the unicellular cyanobacterium Synechococcus elongatus. Each protease consists of a unique proteolytic core comprised of two separate Clp subunits, one with ClpP1 and ClpP2, the other with ClpP3 and ClpR. Each core also associates with a particular HSP100 chaperone partner, ClpC in the case of the ClpP3/R core, and ClpX for the ClpP1/P2 core. The two adaptor proteins, ClpS1 and ClpS2 also interact with the ClpC chaperone protein, likely increasing the range of protein substrates targeted by the Clp protease in cyanobacteria. We also reveal the possible existence of a third Clp protease in Synechococcus, one which associates with the internal membrane network. Altogether, we show that presence of several distinctive Clp proteases in cyanobacteria, a feature which contrasts from that in most other organisms.
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36.
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37.
  • Stanne, Tara M, 1979, et al. (författare)
  • Genetic variation at the BDNF locus: evidence for association with long-term outcome after ischemic stroke.
  • 2014
  • Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 9:12
  • Tidskriftsartikel (refereegranskat)abstract
    • Rates and extent of recovery after stroke vary considerably between individuals and genetic factors are thought to contribute to post-stroke outcome. Brain-derived neurotrophic factor (BDNF) plays important roles in brain plasticity and repair and has been shown to be involved in stroke severity, recovery, and outcome in animal models. Few clinical studies on BDNF genotypes in relation to ischemic stroke have been performed. The aims of the present study are therefore to investigate whether genetic variation at the BDNF locus is associated with initial stroke severity, recovery and/or short-term and long-term functional outcome after ischemic stroke.
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38.
  • Stanne, Tara M, 1979, et al. (författare)
  • Identification of new protein substrates for the chloroplast ATP-dependent Clp protease supports its constitutive role in Arabidopsis.
  • 2009
  • Ingår i: The Biochemical journal. - 1470-8728. ; 417:1, s. 257-68
  • Tidskriftsartikel (refereegranskat)abstract
    • The ATP-dependent Clp protease in plant chloroplasts consists of a heterogeneous proteolytic core containing multiple ClpP and ClpR paralogues. In this study, we have examined in detail the only viable knockout mutant to date of one of these subunits in Arabidopsis thaliana, ClpR1. Loss of ClpR1 caused a slow-growth phenotype, with chlorotic leaves during early development that later partially recovered upon maturity. Analysis of the Clp proteolytic core in the clpR1 mutant (clpR1-1) revealed approx. 10% of the wild-type levels remaining, probably due to a relative increase in the closely related ClpR3 protein and its partial substitution of ClpR1 in the core complex. A proteomic approach using an in organello proteolytic assay revealed 19 new potential substrates for the chloroplast Clp protease. Many of these substrates were constitutive enzymes involved in different metabolic pathways, including photosynthetic carbon fixation, nitrogen metabolism and chlorophyll/haem biosynthesis, whereas others function in housekeeping roles such as RNA maturation, protein synthesis and maturation, and recycling processes. In contrast, degradation of the stress-related chloroplast proteins Hsp21 (heat-shock protein 21) and lipoxygenase 2 was unaffected in the clpR1-1 line and thus not facilitated by the Clp protease. Overall, we show that the chloroplast Clp protease is principally a constitutive enzyme that degrades numerous stromal proteins, a feature that almost certainly underlies its vital importance for chloroplast function and plant viability.
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39.
  • Stanne, Tara M, 1979, et al. (författare)
  • Longitudinal Study Reveals Long-Term Proinflammatory Proteomic Signature After Ischemic Stroke Across Subtypes
  • 2022
  • Ingår i: Stroke. - : Ovid Technologies (Wolters Kluwer Health). - 0039-2499 .- 1524-4628. ; 53:9, s. 2847-2858
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Inflammation contributes both to the pathogenesis of stroke and the response to brain injury. We aimed to identify proteins reflecting the acute-phase response and proteins more likely to reflect proinflammatory processes present before stroke by broadly profiling inflammation-related plasma proteins in a longitudinal ischemic stroke study. Methods: Participants were from a Swedish ischemic stroke cohort (SAHLSIS [Sahlgrenska Academy Study on Ischemic Stroke], n=600 cases and n=600 controls). Plasma levels of 65 proteins including chemokines, interleukins, surface molecules, and immune receptors were measured once in controls and at 3x in cases: during the acute phase, after 3 months, and for a subgroup (n=223) at 7-year follow-up. Associations between proteins and ischemic stroke or subtype were investigated in multivariable binary regression models corrected for age, sex, vascular risk factors, and multiple testing. Results: In the acute phase, 48 proteins were significantly and independently associated with ischemic stroke (false discovery rate adjusted P<0.05). At 3-month follow-up, 51 proteins and at 7-year follow-up 50 proteins were associated with ischemic stroke. The majority of proteins were upregulated in cases compared with controls (n=34 at all time points) and the most upregulated were CXCL5 (CXC chemokine ligand 5) and OSM (oncostatin M). Generally, large artery and cardioembolic stroke had the highest protein levels. However, several interesting subtype-specific differences were also detected at each time point. Conclusions: We found inflammation-related proteins that were differentially regulated in ischemic stroke cases compared with controls only in the acute phase and others that remained elevated also at later time points. This latter group of proteins could reflect underlying pathophysiological processes of relevance. Future studies both in terms of disease risk and prognostication are warranted.
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40.
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41.
  • Stanne, Tara M, 1979, et al. (författare)
  • Low Circulating Acute Brain-Derived Neurotrophic Factor Levels Are Associated With Poor Long-Term Functional Outcome After Ischemic Stroke.
  • 2016
  • Ingår i: Stroke; a journal of cerebral circulation. - 1524-4628 .- 0039-2499. ; 47:7, s. 1943-1945
  • Tidskriftsartikel (refereegranskat)abstract
    • Brain-derived neurotrophic factor (BDNF) plays important roles in brain plasticity and repair, and it influences stroke outcomes in animal models. Circulating BDNF concentrations are lowered in patients with traumatic brain injury, and low BDNF predicts poor recovery after this injury. We sought to investigate whether circulating concentrations of BDNF are altered in the acute phase of ischemic stroke and whether they are associated with short- or long-term functional outcome.
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42.
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43.
  • Söderholm, M, et al. (författare)
  • Exome array analysis of ischaemic stroke : results from a southern Swedish study
  • 2016
  • Ingår i: European Journal of Neurology. - : Wiley. - 1351-5101 .- 1468-1331. ; 23:12, s. 1722-1728
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND AND PURPOSE: Genome-wide association (GWA) studies have identified a few risk loci for ischaemic stroke, but these variants explain only a small part of the genetic contribution to the disease. Coding variants associated with amino acid substitutions or premature termination of protein synthesis could have a large effect on disease risk. We performed an exome array analysis for ischaemic stroke.METHODS: Patients with ischaemic stroke (n = 2385) and control subjects (n = 6077) from three Swedish studies were genotyped with the Illumina HumanOmniExpressExome BeadChip. Single-variant association analysis and gene-based tests were performed of exome variants with minor allele frequency of < 5%. A separate GWA analysis was also performed, based on 700 000 genotyped common markers and subsequent imputation.RESULTS: No exome variant or gene was significantly associated with all ischaemic stroke after Bonferroni correction (all P > 1.8 × 10(-6) for single-variant and >4.15 × 10(-6) for gene-based analysis). The strongest association in single-variant analysis was found for a missense variant in the DNAH11 gene (rs143362381; P = 5.01 × 10(-6) ). In gene-based tests, the strongest association was for the ZBTB20 gene (P = 7.9 × 10(-5) ). The GWA analysis showed that the sample was homogenous (median genomic inflation factor = 1.006). No genome-wide significant association with overall ischaemic stroke risk was found. However, previously reported associations for the PITX2 and ZFHX3 gene loci with cardioembolic stroke subtype were replicated (P = 7 × 10(-15) and 6 × 10(-3) ).CONCLUSIONS: This exome array analysis did not identify any single variants or genes reaching the pre-defined significance level for association with ischaemic stroke. Further studies on exome variants should be performed in even larger, well-defined and subtyped samples.
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44.
  • Söderholm, Martin, et al. (författare)
  • Genome-wide association meta-analysis of functional outcome after ischemic stroke
  • 2019
  • Ingår i: Neurology. - 1526-632X. ; 92:12, s. 1271-1283
  • Tidskriftsartikel (refereegranskat)abstract
    • OBJECTIVE: To discover common genetic variants associated with poststroke outcomes using a genome-wide association (GWA) study. METHODS: The study comprised 6,165 patients with ischemic stroke from 12 studies in Europe, the United States, and Australia included in the GISCOME (Genetics of Ischaemic Stroke Functional Outcome) network. The primary outcome was modified Rankin Scale score after 60 to 190 days, evaluated as 2 dichotomous variables (0-2 vs 3-6 and 0-1 vs 2-6) and subsequently as an ordinal variable. GWA analyses were performed in each study independently and results were meta-analyzed. Analyses were adjusted for age, sex, stroke severity (baseline NIH Stroke Scale score), and ancestry. The significance level was p < 5 × 10-8. RESULTS: We identified one genetic variant associated with functional outcome with genome-wide significance (modified Rankin Scale scores 0-2 vs 3-6, p = 5.3 × 10-9). This intronic variant (rs1842681) in the LOC105372028 gene is a previously reported trans-expression quantitative trait locus for PPP1R21, which encodes a regulatory subunit of protein phosphatase 1. This ubiquitous phosphatase is implicated in brain functions such as brain plasticity. Several variants detected in this study demonstrated suggestive association with outcome (p < 10-5), some of which are within or near genes with experimental evidence of influence on ischemic stroke volume and/or brain recovery (e.g., NTN4, TEK, and PTCH1). CONCLUSIONS: In this large GWA study on functional outcome after ischemic stroke, we report one significant variant and several variants with suggestive association to outcome 3 months after stroke onset with plausible mechanistic links to poststroke recovery. Future replication studies and exploration of potential functional mechanisms for identified genetic variants are warranted.
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45.
  • Wu, O., et al. (författare)
  • Big Data Approaches to Phenotyping Acute Ischemic Stroke Using Automated Lesion Segmentation of Multi-Center Magnetic Resonance Imaging Data
  • 2019
  • Ingår i: Stroke. - : Ovid Technologies (Wolters Kluwer Health). - 0039-2499 .- 1524-4628. ; 50:7, s. 1734-1741
  • Tidskriftsartikel (refereegranskat)abstract
    • Background and Purpose- We evaluated deep learning algorithms' segmentation of acute ischemic lesions on heterogeneous multi-center clinical diffusion-weighted magnetic resonance imaging (MRI) data sets and explored the potential role of this tool for phenotyping acute ischemic stroke. Methods- Ischemic stroke data sets from the MRI-GENIE (MRI-Genetics Interface Exploration) repository consisting of 12 international genetic research centers were retrospectively analyzed using an automated deep learning segmentation algorithm consisting of an ensemble of 3-dimensional convolutional neural networks. Three ensembles were trained using data from the following: (1) 267 patients from an independent single-center cohort, (2) 267 patients from MRI-GENIE, and (3) mixture of (1) and (2). The algorithms' performances were compared against manual outlines from a separate 383 patient subset from MRI-GENIE. Univariable and multivariable logistic regression with respect to demographics, stroke subtypes, and vascular risk factors were performed to identify phenotypes associated with large acute diffusion-weighted MRI volumes and greater stroke severity in 2770 MRI-GENIE patients. Stroke topography was investigated. Results- The ensemble consisting of a mixture of MRI-GENIE and single-center convolutional neural networks performed best. Subset analysis comparing automated and manual lesion volumes in 383 patients found excellent correlation (rho=0.92; P<0.0001). Median (interquartile range) diffusion-weighted MRI lesion volumes from 2770 patients were 3.7 cm(3) (0.9-16.6 cm(3)). Patients with small artery occlusion stroke subtype had smaller lesion volumes (P<0.0001) and different topography compared with other stroke subtypes. Conclusions- Automated accurate clinical diffusion-weighted MRI lesion segmentation using deep learning algorithms trained with multi-center and diverse data is feasible. Both lesion volume and topography can provide insight into stroke subtypes with sufficient sample size from big heterogeneous multi-center clinical imaging phenotype data sets.
  •  
46.
  • Wu, Ona, et al. (författare)
  • Big Data Approaches to Phenotyping Acute Ischemic Stroke Using Automated Lesion Segmentation of Multi-Center Magnetic Resonance Imaging Data
  • 2019
  • Ingår i: Stroke. - 1524-4628. ; 50:7, s. 1734-1741
  • Tidskriftsartikel (refereegranskat)abstract
    • Background and Purpose- We evaluated deep learning algorithms' segmentation of acute ischemic lesions on heterogeneous multi-center clinical diffusion-weighted magnetic resonance imaging (MRI) data sets and explored the potential role of this tool for phenotyping acute ischemic stroke. Methods- Ischemic stroke data sets from the MRI-GENIE (MRI-Genetics Interface Exploration) repository consisting of 12 international genetic research centers were retrospectively analyzed using an automated deep learning segmentation algorithm consisting of an ensemble of 3-dimensional convolutional neural networks. Three ensembles were trained using data from the following: (1) 267 patients from an independent single-center cohort, (2) 267 patients from MRI-GENIE, and (3) mixture of (1) and (2). The algorithms' performances were compared against manual outlines from a separate 383 patient subset from MRI-GENIE. Univariable and multivariable logistic regression with respect to demographics, stroke subtypes, and vascular risk factors were performed to identify phenotypes associated with large acute diffusion-weighted MRI volumes and greater stroke severity in 2770 MRI-GENIE patients. Stroke topography was investigated. Results- The ensemble consisting of a mixture of MRI-GENIE and single-center convolutional neural networks performed best. Subset analysis comparing automated and manual lesion volumes in 383 patients found excellent correlation (ρ=0.92; P<0.0001). Median (interquartile range) diffusion-weighted MRI lesion volumes from 2770 patients were 3.7 cm3 (0.9-16.6 cm3). Patients with small artery occlusion stroke subtype had smaller lesion volumes ( P<0.0001) and different topography compared with other stroke subtypes. Conclusions- Automated accurate clinical diffusion-weighted MRI lesion segmentation using deep learning algorithms trained with multi-center and diverse data is feasible. Both lesion volume and topography can provide insight into stroke subtypes with sufficient sample size from big heterogeneous multi-center clinical imaging phenotype data sets.
  •  
47.
  • Åberg, Daniel, 1973, et al. (författare)
  • Serum IGFBP-1 Concentration as a Predictor of Outcome after Ischemic Stroke—A Prospective Observational Study
  • 2023
  • Ingår i: International Journal of Molecular Sciences. - 1422-0067. ; 24:11
  • Tidskriftsartikel (refereegranskat)abstract
    • Insulin-like growth factor-binding protein-1 (IGFBP-1) regulates insulin-like growth factor- I (IGF-I) bioactivity, and is a central player in normal growth, metabolism, and stroke recovery. However, the role of serum IGFBP-1 (s-IGFBP-1) after ischemic stroke is unclear. We determined whether s-IGFBP-1 is predictive of poststroke outcome. The study population comprised patients (n = 470) and controls (n = 471) from the Sahlgrenska Academy Study on Ischemic Stroke (SAHLSIS). Functional outcome was evaluated after 3 months, 2, and 7 years using the modified Rankin Scale (mRS). Survival was followed for a minimum of 7 years or until death. S-IGFBP-1 was increased after 3 months (p < 0.01), but not in the acute phase after stroke, compared with the controls. Higher acute s-IGFBP-1 was associated with poor functional outcome (mRS score > 2) after 7 years [fully adjusted odds ratio (OR) per log increase 2.9, 95% confidence interval (CI): 1.4-5.9]. Moreover, higher s-IGFBP-1 after 3 months was associated with a risk of poor functional outcome after 2 and 7 years (fully adjusted: OR 3.4, 95% CI: 1.4–8.5 and OR 5.7, 95% CI: 2.5–12.8, respectively) and with increased mortality risk (fully adjusted: HR 2.0, 95% CI: 1.1–3.7). Thus, high acute s-IGFBP-1 was only associated with poor functional outcome after 7 years, whereas s-IGFBP-1 after 3 months was an independent predictor of poor long-term functional outcome and poststroke mortality.
  •  
48.
  • Åberg, N David, 1970, et al. (författare)
  • Genetic variation at the IGF1 locus shows association with post-stroke outcome and to circulating IGF1.
  • 2013
  • Ingår i: European journal of endocrinology / European Federation of Endocrine Societies. - 1479-683X. ; 169:6, s. 759-65
  • Tidskriftsartikel (refereegranskat)abstract
    • In humans, serum IGF1 (s-IGF1) is associated with outcome after ischemic stroke (IS). Therefore variation at the IGF1 locus could also associate with both IS and s-IGF1. We investigated whether genetic variation at the IGF1 locus is associated with i) s-IGF1, ii) IS occurrence, iii) IS severity, and iv) post-stroke outcome.
  •  
49.
  • Åberg, N David, 1970, et al. (författare)
  • Serum erythropoietin and outcome after ischaemic stroke: a prospective study.
  • 2016
  • Ingår i: BMJ open. - : BMJ. - 2044-6055. ; 6:2
  • Tidskriftsartikel (refereegranskat)abstract
    • Erythropoietin (EPO), which is inversely associated with blood haemoglobin (Hb), exerts neuroprotective effects in experimental ischaemic stroke (IS). However, clinical treatment trials have so far been negative. Here, in patients with IS, we analysed whether serum EPO is associated with (1) initial stroke severity, (2) recovery and (3) functional outcome.
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