| 21. |
- Klaric, Lucija, et al.
(författare)
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Mendelian randomisation identifies alternative splicing of the FAS death receptor as a mediator of severe COVID-19.
- 2021
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Ingår i: medRxiv : the preprint server for health sciences. - : Cold Spring Harbor Laboratory. ; , s. 1-28
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Severe COVID-19 is characterised by immunopathology and epithelial injury. Proteomic studies have identified circulating proteins that are biomarkers of severe COVID-19, but cannot distinguish correlation from causation. To address this, we performed Mendelian randomisation (MR) to identify proteins that mediate severe COVID-19. Using protein quantitative trait loci (pQTL) data from the SCALLOP consortium, involving meta-analysis of up to 26,494 individuals, and COVID-19 genome-wide association data from the Host Genetics Initiative, we performed MR for 157 COVID-19 severity protein biomarkers. We identified significant MR results for five proteins: FAS, TNFRSF10A, CCL2, EPHB4 and LGALS9. Further evaluation of these candidates using sensitivity analyses and colocalization testing provided strong evidence to implicate the apoptosis-associated cytokine receptor FAS as a causal mediator of severe COVID-19. This effect was specific to severe disease. Using RNA-seq data from 4,778 individuals, we demonstrate that the pQTL at the FAS locus results from genetically influenced alternate splicing causing skipping of exon 6. We show that the risk allele for very severe COVID-19 increases the proportion of transcripts lacking exon 6, and thereby increases soluble FAS. Soluble FAS acts as a decoy receptor for FAS-ligand, inhibiting apoptosis induced through membrane-bound FAS. In summary, we demonstrate a novel genetic mechanism that contributes to risk of severe of COVID-19, highlighting a pathway that may be a promising therapeutic target.
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| 22. |
- Kurtovic, Sanela, et al.
(författare)
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Diverging alternative splicing fingerprints in the transforming growth factor-β signaling pathway identified in thoracic aortic aneurysms.
- 2011
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Ingår i: Molecular medicine (Cambridge, Mass.). - : Springer Science and Business Media LLC. - 1528-3658 .- 1076-1551. ; 17:7-8, s. 665-75
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Tidskriftsartikel (refereegranskat)abstract
- Impaired regulation of the transforming growth factor-β (TGFβ) signaling pathway has been linked to thoracic aortic aneurysm (TAA). Previous work has indicated that differential splicing is a common phenomenon, potentially influencing the function of proteins. In the present study we investigated the occurrence of differential splicing in the TGFβ pathway associated with TAA in patients with bicuspid aortic valve (BAV) and tricuspid aortic valve (TAV). Affymetrix human exon arrays were applied to 81 intima/media tissue samples from dilated (n = 51) and nondilated (n = 30) aortas of TAV and BAV patients. To analyze the occurrence of alternative splicing in the TGFβ pathway, multivariate techniques, including principal component analysis and OPLS-DA (orthogonal partial least squares to latent structures discriminant analysis), were applied on all exons (n = 614) of the TGFβ pathway. The scores plot, based on the splice index of individual exons, showed separate clusters of patients with both dilated and nondilated aorta, thereby illustrating the potential importance of alternative splicing in TAA. In total, differential splicing was detected in 187 exons. Furthermore, the pattern of alternative splicing is clearly differs between TAV and BAV patients. Differential splicing was specific for BAV and TAV patients in 40 and 86 exons, respectively, and splicings of 61 exons were shared between the two phenotypes. The occurrence of differential splicing was demonstrated in selected genes by reverse transcription-polymerase chain reaction. In summary, alternative splicing is a common feature of TAA formation. Our results suggest that dilatation in TAV and BAV patients has different alternative splicing fingerprints in the TGFβ pathway.
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| 23. |
- Locke, Adam E, et al.
(författare)
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Genetic studies of body mass index yield new insights for obesity biology.
- 2015
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 518:7538, s. 197-401
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Tidskriftsartikel (refereegranskat)abstract
- Obesity is heritable and predisposes to many diseases. To understand the genetic basis of obesity better, here we conduct a genome-wide association study and Metabochip meta-analysis of body mass index (BMI), a measure commonly used to define obesity and assess adiposity, in up to 339,224 individuals. This analysis identifies 97 BMI-associated loci (P < 5 × 10(-8)), 56 of which are novel. Five loci demonstrate clear evidence of several independent association signals, and many loci have significant effects on other metabolic phenotypes. The 97 loci account for ∼2.7% of BMI variation, and genome-wide estimates suggest that common variation accounts for >20% of BMI variation. Pathway analyses provide strong support for a role of the central nervous system in obesity susceptibility and implicate new genes and pathways, including those related to synaptic function, glutamate signalling, insulin secretion/action, energy metabolism, lipid biology and adipogenesis.
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| 24. |
- Macdonald-Dunlop, Erin, et al.
(författare)
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Mapping genetic determinants of 184 circulating proteins in 26,494 individuals to connect proteins and diseases
- 2021
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- We performed the largest genome-wide meta-analysis (GWAMA) (Max N=26,494) of the levels of 184 cardiovascular-related plasma protein levels to date and reported 592 independent loci (pQTL) associated with the level of at least one protein (1308 significant associations, median 6 per protein). We estimated that only between 8-37% of testable pQTL overlap with established expression quantitative trait loci (eQTL) using multiple methods, while 132 out of 1064 lead variants show evidence for transcription factor binding, and found that 75% of our pQTL are known DNA methylation QTL. We highlight the variation in genetic architecture between proteins and that proteins share genetic architecture with cardiometabolic complex traits. Using cis-instrument Mendelian randomisation (MR), we infer causal relationships for 11 proteins, recapitulating the previously reported relationship between PCSK9 and LDL cholesterol, replicating previous pQTL MR findings and discovering 16 causal relationships between protein levels and disease. Our MR results highlight IL2-RA as a candidate for drug repurposing for Crohn’s Disease as well as 2 novel therapeutic targets: IL-27 (Crohn’s disease) and TNFRSF14 (Inflammatory bowel disease, Multiple sclerosis and Ulcerative colitis). We have demonstrated the discoveries possible using our pQTL and highlight the potential of this work as a resource for genetic epidemiology.
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| 25. |
- Maleki, Shohreh, et al.
(författare)
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Identification of a novel flow-mediated gene expression signature in patients with bicuspid aortic valve
- 2013
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Ingår i: Journal of Molecular Medicine. - : Springer-Verlag New York. - 0946-2716 .- 1432-1440. ; 91:1, s. 129-139
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Tidskriftsartikel (refereegranskat)abstract
- Rationale: Individuals with bicuspid aortic valve (BAV) are at significantly higher risk of developing serious aortic complications including aortic aneurysm and dissection than individuals with a tricuspid aortic valve (TAV). Studies have indicated an altered aortic blood flow in patients with BAV, however the extent to which altered flow may influence the pathological state of BAV aorta is still unclear.Objective: To dissect flow-mediated gene expression potentially leading to increased aneurysm susceptibility in patients with BAV.Methods and Results: A large collection of publically available microarray data sets were screened for consistent co-expression with KLF2, KLF4, TIE1, THBD, and PKD2, five previously well-characterized flow-regulated genes. This identified 122 genes with coexpression probability of >0.5. Of these, 44 genes satisfied two additional filtering criteria in ascending aorta (127 arrays). The criteria were significant correlation with one or more of the 5 query genes (R>0.40) and differential expression between patients with BAV and TAV. No gene fulfilled the criteria in mammary artery (88 arrays). A large proportion of the identified genes were angiogenesis related genes. Further, 55% of the genes differentially expressed between BAV and TAV showed differential expression in disturbed vs. uniform flow pattern regions in rat aorta. Protein expression of ZFP36, PKD2 and GPR116 were analyzed by immunohistochemistry and their association with BAV were further discussed.Conclusions: With a new strategy to dissect flow-mediated gene expression, we identified novel genes associated with valve morphology. The complex pattern of blood flow, as a consequence of BAV
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| 26. |
- Matikainen, Niina, et al.
(författare)
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Genetic Variation in SULF2 Is Associated with Postprandial Clearance of Triglyceride-Rich Remnant Particles and Triglyceride Levels in Healthy Subjects.
- 2013
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Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 8:11
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Tidskriftsartikel (refereegranskat)abstract
- Nonfasting (postprandial) triglyceride concentrations have emerged as a clinically significant cardiovascular disease risk factor that results from accumulation of remnant triglyceride-rich lipoproteins (TRLs) in the circulation. The remnant TRLs are cleared from the circulation by hepatic uptake, but the specific mechanisms involved are unclear. The syndecan-1 heparan sulfate proteoglycan (HSPG) pathway is important for the hepatic clearance of remnant TRLs in mice, but its relevance in humans is unclear.
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| 27. |
- Paloschi, Valentina, et al.
(författare)
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Impaired Splicing of Fibronectin Is Associated With Thoracic Aortic Aneurysm Formation in Patients With Bicuspid Aortic Valve
- 2011
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Ingår i: Arteriosclerosis, Thrombosis and Vascular Biology. - : American Heart Association. - 1079-5642 .- 1524-4636. ; 31:3, s. 691-697
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE:Thoracic aortic aneurysm is a common complication in patients with bicuspid aortic valve (BAV). Alternatively spliced extra domain A (EDA) of fibronectin (FN) has an essential role in tissue repair. Here we analyze the expression of FN spliceforms in dilated and nondilated ascending aorta of tricuspid aortic valve (TAV) and BAV patients.METHODS AND RESULTS:The mRNA expression was analyzed in the ascending aorta by Affymetrix Exon arrays in patients with TAV (n=40) and BAV (n=69). EDA and extra domain B (EDB) expression was increased in dilated aorta from TAV patients compared with nondilated aorta (P<0.001 and P<0.05, respectively). In contrast, EDA expression was not increased in dilated aorta from BAV patients (P=0.25), whereas EDB expression was upregulated (P<0.01). The expression of EDA correlated with maximum aortic diameter in TAV (ρ=0.58) but not in BAV (ρ=0.15) patients. Protein analyses of EDA-FN showed concordant results. Transforming growth factor-β treatment influenced the splicing of FN and enhanced the formation of EDA-containing FN in cultured medial cells from TAV patients but not in cells derived from BAV patients. Gene set enrichment analysis together with multivariate and univariate data analyses of mRNA expression suggested that differences in the transforming growth factor-β signaling pathway may explain the impaired EDA inclusion in BAV patients.CONCLUSIONS:Decreased EDA expression may contribute to increased aneurysm susceptibility of BAV patients.
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| 28. |
- Paramel, Geena, 1985-, et al.
(författare)
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CARD8 gene encoding a protein of innate immunity is expressed in human atherosclerosis and associated with markers of inflammation
- 2013
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Ingår i: Clinical Science. - London, United Kingdom : Portland Press. - 0143-5221 .- 1470-8736. ; 125:8, s. 401-407
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Tidskriftsartikel (refereegranskat)abstract
- Inflammation is a key factor in the development of atherosclerotic coronary artery disease. It is promoted through the inflammasome, a molecular machine that produces IL (interleukin)-1 beta in response to cholesterol crystal accumulation in macrophages. The CARD8 (caspase recruitment domain 8) protein modulates this process by suppressing caspase 1 and the transcription factor NF-kappa B (nuclear factor kappa B). The expression of CARD8 mRNA was examined in atherosclerotic vascular tissue and the impact on MI (myocardial infarction) of a polymorphism in the CARD8 gene determined. CARD8 mRNA was analysed by microarray of human atherosclerotic tissue and compared with transplant donor arterial tissue. Microarray analysis was performed for proximal genes associated with the rs2043211 locus in plaque. The CARD8 rs2043211 polymorphism was analysed by genotyping of two Swedish MI cohorts, FIA (First Myocardial Infarction in Northern Sweden) and SCARF (Stockholm Coronary Atherosclerosis Risk Factor). The CRP (C-reactive protein) level was measured in both cohorts, but the levels of the pro-inflammatory cytokines IL-1 beta, IL-18, TNF (tumour necrosis factor) and MCP-1 (monocyte chemoattractant protein) were measured in sera available from the SCARF cohort. CARD8 mRNA was highly expressed in atherosclerotic plaques compared with the expression in transplant donor vessel (P < 0.00001). The minor allele was associated with lower expression of CARD8 in the plaques, suggesting that CARD8 may promote inflammation. Carriers of the minor allele of the rs2043211 polymorphism also displayed lower circulating CRP and lower levels of the pro-atherosclerotic chemokine MCP-1. However, no significant association could be detected between this polymorphism and MI in the two cohorts. Genetic alterations in the CARD8 gene therefore seem to be of limited importance for the development of MI.
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| 29. |
- Paramel Varghese, Geena, 1985-, et al.
(författare)
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Expression of CARD8 in human atherosclerosis and its regulation of inflammatory proteins in human endothelial cells
- 2020
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- The Caspase activation and recruitment domain 8 (CARD8) protein is a component of innate immunity and overexpression of CARD8 mRNA was previously identified in atherosclerosis. However, very little is known about the regulation of CARD8 in endothelial cells and atherosclerosis. The aim of this study was to investigate CARD8 in the regulation of cytokine and chemokine expression in endothelial cells. Sections of human atherosclerotic lesions and non-atherosclerotic arteries were immunostained for CARD8 protein. Expression of CARD8 was correlated to mediators of inflammation in atherosclerotic lesions using Biobank of Karolinska Endarterectomies microarray data. The CARD8 mRNA was knocked-down in human umbilical vein endothelial cells (HUVECs) in vitro, followed by quantitative RT-PCR analysis and OLINK Proteomics. Endothelial and smooth muscle cells in arterial tissue expressed CARD8 and CARD8 correlated with vWF, CD163 and the expression of inflammatory genes, such as CXCL1, CXCL6 and PDGF-A in plaque. Knock-down of CARD8 in HUVECs significantly altered proteins involved in inflammatory response, such as CXCL1, CXCL6, PDGF-A, MCP-1 and IL-6. The present study suggest that CARD8 regulate the expression of cytokines and chemokines in endothelial cells and atherosclerotic lesions, suggesting that CARD8 plays a significant role in endothelial activation.
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| 30. |
- Paramel Varghese, Geena, 1985-, et al.
(författare)
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NLRP3 Inflammasome Expression and Activation in Human Atherosclerosis
- 2016
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Ingår i: Journal of the American Heart Association. - Hoboken, USA : Wiley-Blackwell Publishing Inc.. - 2047-9980. ; 5:5
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Tidskriftsartikel (refereegranskat)abstract
- Background: The NLR family, pyrin domain containing 3 (NLRP3) inflammasome is an interleukin (IL)-1β and IL-18 cytokine processing complex that is activated in inflammatory conditions. The role of the NLRP3 inflammasome in the pathogenesis of atherosclerosis and myocardial infarction is not fully understood.Methods and Results: Atherosclerotic plaques were analyzed for transcripts of the NLRP3 inflammasome, and for IL-1β release. The Swedish First-ever myocardial Infarction study in Ac-county (FIA) cohort consisting of DNA from 555 myocardial infarction patients and 1016 healthy individuals was used to determine the frequency of 4 single nucleotide polymorphisms (SNPs) from the downstream regulatory region of NLRP3. Expression of NLRP3, Apoptosis-associated speck-like protein containing a CARD (ASC), caspase-1 (CASP1), IL1B, and IL18 mRNA was significantly increased in atherosclerotic plaques compared to normal arteries. The expression of NLRP3 mRNA was significantly higher in plaques of symptomatic patients when compared to asymptomatic ones. CD68-positive macrophages were observed in the same areas of atherosclerotic lesions as NLRP3 and ASC expression. Occasionally, expression of NLRP3 and ASC was also present in smooth muscle cells. Cholesterol crystals and ATP induced IL-1β release from lipopolysaccharide-primed human atherosclerotic lesion plaques. The minor alleles of the variants rs4266924, rs6672995, and rs10733113 were associated with NLRP3 mRNA levels in peripheral blood mononuclear cells but not with the risk of myocardial infarction.Conclusions: Our results indicate a possible role of the NLRP3 inflammasome and its genetic variants in the pathogenesis of atherosclerosis.
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