| 1. |
- Pulit, SL, et al.
(författare)
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Loci associated with ischaemic stroke and its subtypes (SiGN): a genome-wide association study.
- 2016
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Ingår i: The Lancet. Neurology. - 1474-4465. ; 15:2, s. 174-84
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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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| 2. |
- Bonkhoff, A. K., et al.
(författare)
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Sex-specific lesion pattern of functional outcomes after stroke
- 2022
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Ingår i: Brain Communications. - : Oxford University Press (OUP). - 2632-1297. ; 4:2
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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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| 3. |
- Bonkhoff, A. K., et al.
(författare)
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Outcome after acute ischemic stroke is linked to sex-specific lesion patterns
- 2021
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 12:1
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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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| 4. |
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| 6. |
- Cole, J. W., et al.
(författare)
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The copy number variation and stroke (CaNVAS) risk and outcome study
- 2021
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 16:4 April
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Tidskriftsartikel (refereegranskat)abstract
- Background and purpose The role of copy number variation (CNV) variation in stroke susceptibility and outcome has yet to be explored. The Copy Number Variation and Stroke (CaNVAS) Risk and Outcome study addresses this knowledge gap. Methods Over 24,500 well-phenotyped IS cases, including IS subtypes, and over 43,500 controls have been identified, all with readily available genotyping on GWAS and exome arrays, with case measures of stroke outcome. To evaluate CNV-associated stroke risk and stroke outcome it is planned to: 1) perform Risk Discovery using several analytic approaches to identify CNVs that are associated with the risk of IS and its subtypes, across the age-, sex- and ethnicity-spectrums; 2) perform Risk Replication and Extension to determine whether the identified stroke-associated CNVs replicate in other ethnically diverse datasets and use biomarker data (e.g. methylation, proteomic, RNA, miRNA, etc.) to evaluate how the identified CNVs exert their effects on stroke risk, and lastly; 3) perform outcome-based Replication and Extension analyses of recent findings demonstrating an inverse relationship between CNV burden and stroke outcome at 3 months (mRS), and then determine the key CNV drivers responsible for these associations using existing biomarker data. Results The results of an initial CNV evaluation of 50 samples from each participating dataset are presented demonstrating that the existing GWAS and exome chip data are excellent for the planned CNV analyses. Further, some samples will require additional considerations for analysis, however such samples can readily be identified, as demonstrated by a sample demonstrating clonal mosaicism. Conclusion The CaNVAS study will cost-effectively leverage the numerous advantages of using existing case-control data sets, exploring the relationships between CNV and IS and its subtypes, and outcome at 3 months, in both men and women, in those of African and European-Caucasian descent, this, across the entire adult-age spectrum. Copyright: This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.
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| 7. |
- Grännö, O., et al.
(författare)
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Preclinical protein signatures in blood predict Crohn's disease and Ulcerative colitis several years before the diagnosis
- 2024
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Ingår i: Journal of Crohn's & Colitis. - : Oxford University Press. - 1873-9946 .- 1876-4479. ; 18:Suppl. 1, s. I660-I661
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Background: We aimed to identify protein signatures predictive of a future diagnosis of inflammatory bowel disease (IBD).Methods: We conducted a case-control study, nested within large population-based cohorts with biorepositories. Samples were obtained from individuals who later in life were diagnosed with IBD (preclinical cases) and compared with age and sex-matched individuals who remained free from IBD during follow-up (controls). Using proximity extension assays (Olink, Uppsala), we measured 176 proteins. We applied regularized logistic regression to identify protein signatures of preclinical disease in serum from the discovery cohort (n=312). Their performance was validated in an external preclinical cohort (n=222). The biological relevance of identified proteins was further assessed in an inception cohort (n=144). Finally, we used an IBD twin cohort (n=327) to examine the impact of genetic and shared environmental factors on identified proteins.Results: We identified 34 proteins associated with preclinical Crohn’s disease (CD) in the discovery cohort (Pfalse discovery rate <0.10), with 9 confirmed in the validation cohort (Pfalse discovery rate <0.05). For preclinical ulcerative colitis (UC), 45 proteins were identified and 12 validated (Fig. 1A-B). In the discovery cohort, a signature of 29 proteins differentiated preclinical CD cases from controls with an AUC of 0.85 (Fig. 1G). Its performance was confirmed when applied to the preclinical validation cohort (AUC=0.84, Fig. 1H). Moreover, the signature had excellent capacity to differentiate newly diagnosed CD from healthy controls in the inception cohort (AUC = 0.99, Fig. 1I). The preclinical UC signature had a significant, but albeit lower, predictive capacity in the discovery (AUC=0.77), validation (AUC=0.67) and inception cohort (AUC=0.90, Fig. 1G-I).15 of 17 proteins associated with preclinical IBD demonstrated significantly higher intra-pair correlation coefficients in healthy monozygotic- compared to dizygotic twin pairs, indicating an influence from genetic factors on the regulation of these protein markers. The preclinical signature for CD demonstrated an AUC of 0.87 when comparing twins with preclinical CD (n=10) to matched external healthy twins. However, its predictive capacity was lower when comparing preclinical CD twins with their healthy twin siblings (AUC=0.58), i.e., when accounting for genetic and shared environmental factors. The difference in AUC estimates in the twin cohort was not significant (P=0.07).
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| 8. |
- Lutgendorff, Femke, et al.
(författare)
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Probiotics prevent intestinal barrier dysfunction in acute pancreatitis in rats via induction of ileal mucosal glutathione biosynthesis.
- 2009
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 4:2, s. e4512-
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: During acute pancreatitis (AP), oxidative stress contributes to intestinal barrier failure. We studied actions of multispecies probiotics on barrier dysfunction and oxidative stress in experimental AP. METHODOLOGY/PRINCIPAL FINDINGS: Fifty-three male Spraque-Dawley rats were randomly allocated into five groups: 1) controls, non-operated, 2) sham-operated, 3) AP, 4) AP and probiotics and 5) AP and placebo. AP was induced by intraductal glycodeoxycholate infusion and intravenous cerulein (6 h). Daily probiotics or placebo were administered intragastrically, starting five days prior to AP. After cerulein infusion, ileal mucosa was collected for measurements of E. coli K12 and (51)Cr-EDTA passage in Ussing chambers. Tight junction proteins were investigated by confocal immunofluorescence imaging. Ileal mucosal apoptosis, lipid peroxidation, and glutathione levels were determined and glutamate-cysteine-ligase activity and expression were quantified. AP-induced barrier dysfunction was characterized by epithelial cell apoptosis and alterations of tight junction proteins (i.e. disruption of occludin and claudin-1 and up-regulation of claudin-2) and correlated with lipid peroxidation (r>0.8). Probiotic pre-treatment diminished the AP-induced increase in E. coli passage (probiotics 57.4+/-33.5 vs. placebo 223.7+/-93.7 a.u.; P<0.001), (51)Cr-EDTA flux (16.7+/-10.1 vs. 32.1+/-10.0 cm/s10(-6); P<0.005), apoptosis, lipid peroxidation (0.42+/-0.13 vs. 1.62+/-0.53 pmol MDA/mg protein; P<0.001), and prevented tight junction protein disruption. AP-induced decline in glutathione was not only prevented (14.33+/-1.47 vs. 8.82+/-1.30 nmol/mg protein, P<0.001), but probiotics even increased mucosal glutathione compared with sham rats (14.33+/-1.47 vs. 10.70+/-1.74 nmol/mg protein, P<0.001). Glutamate-cysteine-ligase activity, which is rate-limiting in glutathione biosynthesis, was enhanced in probiotic pre-treated animals (probiotics 2.88+/-1.21 vs. placebo 1.94+/-0.55 nmol/min/mg protein; P<0.05) coinciding with an increase in mRNA expression of glutamate-cysteine-ligase catalytic (GCLc) and modifier (GCLm) subunits. CONCLUSIONS: Probiotic pre-treatment diminished AP-induced intestinal barrier dysfunction and prevented oxidative stress via mechanisms mainly involving mucosal glutathione biosynthesis.
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| 9. |
- Nylén, H., et al.
(författare)
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O KVV Auger emission versus resonant photoemission at the O K edge of high-Tc superconductors
- 1998
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Ingår i: Physica C: Superconductivity and its Applications. - 0921-4534. ; 300:3-4, s. 161-170
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Tidskriftsartikel (refereegranskat)abstract
- Photoelectron spectroscopy results on single crystals of the superconductors Bi2Sr2CaCu2O8,Bi2Sr 2CuO6, Ba0.6K0.4BiO3 and the semiconductor Ba0.9K0.1BiO3 are reported for the photon energy region around the O K absorption threshold. The development of the O-KVV Auger structure has been carefully monitored as a function of photon energy. A non-monotonic behavior displaying a feature at a constant binding energy of about 14 eV was found for Bi2Sr2CaCu2O8 and Bi2Sr2CuO6 in a narrow photon energy region of 1 eV at the main edge of the O K absorption spectrum around 530 eV. The corresponding enhancement, connected with the autoionization of O 2 p states, is absent in Ba1-xKxBiO3 in contrast to Bi2Sr2CaCu2O8 and Bi2Sr2CuO6. The resonant enhancement is more pronounced for Bi2Sr2CuO6 as compared to Bi2Sr2CaCu2O8, which can be explained by a lower charge carrier concentration in the former case, leading to a more localized nature of intermediate O 2 p states. The model parameters Cu d-d and O p-p Coulomb interactions and the charge transfer energy Δ are estimated from the experiments.
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| 10. |
- Salomon, Benita, 1993-, et al.
(författare)
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Prognostic potential of mucosal proteins in Ulcerative Colitis
- 2024
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Ingår i: Journal of Crohn's & Colitis. - : Oxford University Press. - 1873-9946 .- 1876-4479. ; 18:Suppl. 1, s. I544-I545
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Background: Better prognostic measures for ulcerative colitis (UC) could significantly advance patient care. While the prognostic capacity of circulating proteins in UC has been explored, the role of mucosal proteins remains largely unknown. We examined mucosal protein markers in patients with incident ulcerative colitis and evaluated their prognostic value.Methods: Biopsies from macroscopically inflamed colonic/rectal mucosa of adult patients in the Swedish inception cohort of IBD (SIC IBD) were obtained at diagnosis of UC. Patients were followed prospectively, and clinical data were recorded after 3 and 12 months. Disease course was categorised as indolent or aggressive at 12 months, based on a composite outcome of colectomy, hospital admission for active disease, treatment refractoriness towards ≥2 biological agents; the use of >2 courses of corticosteroids, or a cumulative dose of >2.5 g. Relative estimates of 162 protein markers were assessed in homogenised tissue supernatants, using proximity extension assay technology (Olink Proteomics, Uppsala, Inflammation and Oncology II panel). Mann-Whitney U test, with Benjamini-Hochberg correction was used to identify differentially regulated mucosal proteins in aggressive vs indolent disease course, with a 5% false discovery rate (FDR). Smoothly clipped absolute deviation regularised logistic regression models were used to identify prognostic signatures distinguishing aggressive from indolent disease course. Performance was estimated in a leave-one-out cross-validation and reported as the area under the receiver operating characteristic (ROC) curve (AUC).Results: 117 patients provided a macroscopically inflamed colonic/rectal biopsy at diagnosis of UC. Basic demographics and clinical characteristics are presented in Table 1. Relative protein levels of WFdc2 and CCL20 were significantly lower in lysates from patients developing an aggressive course vs patients developing an indolent course, while estimates of MMP1, CCL11, WISP-1, OPG, RSPO3 and VEGFR2 were higher (Figure 1A). Regularized logistic regression identified signatures restricted to 28 proteins, distinguishing aggressive from indolent UC courses, yielding an AUC of 0.68 (95% confidence interval (CI): 0.56-0.80) for left-out samples (Figure 1B). Incorporating extent of inflammation at diagnosis in the model improved the AUC to 0.71 (95% CI: 0.60-0.83).Conclusion: We identified prognostic mucosal protein signatures associated with future course of ulcerative colitis by analysing inflamed mucosal biopsies that were obtained at diagnosis. These protein markers may highlight pathways of relevance for ulcerative colitis outcomes.
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