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- Saliba-Gustafsson, P., et al.
(author)
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Subclinical atherosclerosis and its progression are modulated by PLIN2 through a feed-forward loop between LXR and autophagy
- 2019
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In: Journal of Internal Medicine. - : Wiley. - 0954-6820 .- 1365-2796. ; 286:6, s. 660-675
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Journal article (peer-reviewed)abstract
- Background Hyperlipidaemia is a major risk factor for cardiovascular disease, and atherosclerosis is the underlying cause of both myocardial infarction and stroke. We have previously shown that the Pro251 variant of perilipin-2 reduces plasma triglycerides and may therefore be beneficial to reduce atherosclerosis development. Objective We sought to delineate putative beneficial effects of the Pro251 variant of perlipin-2 on subclinical atherosclerosis and the mechanism by which it acts. Methods A pan-European cohort of high-risk individuals where carotid intima-media thickness has been assessed was adopted. Human primary monocyte-derived macrophages were prepared from whole blood from individuals recruited by perilipin-2 genotype or from buffy coats from the Karolinska University hospital blood central. Results The Pro251 variant of perilipin-2 is associated with decreased intima-media thickness at baseline and over 30 months of follow-up. Using human primary monocyte-derived macrophages from carriers of the beneficial Pro251 variant, we show that this variant increases autophagy activity, cholesterol efflux and a controlled inflammatory response. Through extensive mechanistic studies, we demonstrate that increase in autophagy activity is accompanied with an increase in liver-X-receptor (LXR) activity and that LXR and autophagy reciprocally activate each other in a feed-forward loop, regulated by CYP27A1 and 27OH-cholesterol. Conclusions For the first time, we show that perilipin-2 affects susceptibility to human atherosclerosis through activation of autophagy and stimulation of cholesterol efflux. We demonstrate that perilipin-2 modulates levels of the LXR ligand 27OH-cholesterol and initiates a feed-forward loop where LXR and autophagy reciprocally activate each other; the mechanism by which perilipin-2 exerts its beneficial effects on subclinical atherosclerosis.
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- Cederstrom, S., et al.
(author)
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New candidate genes for ST-elevation myocardial infarction
- 2020
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In: Journal of Internal Medicine. - : Wiley. - 0954-6820 .- 1365-2796. ; 287:1, s. 66-77
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Journal article (peer-reviewed)abstract
- Background Despite extensive research in atherosclerosis, the mechanisms of coronary atherothrombosis in ST-elevation myocardial infarction (STEMI) patients are undetermined. Objectives Our aim was to find candidate genes involved in STEMI by analysing leucocyte gene expression in STEMI patients, without the influence of secondary inflammation from innate immunity, which was assumed to be a consequence rather than the cause of coronary atherothrombosis. Methods Fifty-one patients were included at coronary angiography because of STEMI. Arterial blood was sampled in the acute phase (P1), at 24-48 h (P2) and at 3 months (P3). Leucocyte RNA was isolated and gene expression analysis was performed by Affymetrix Human Transcriptome Array 2.0. By omission of up- or downregulated genes at P2, secondary changes from innate immunity were excluded. Genes differentially expressed in P1 when compared to the convalescent sample in P3 were determined as genes involved in STEMI. Results Three genes were upregulated at P1 compared to P3; ABCG1 (P = 5.81 x 10(-5)), RAB20 (P = 3.69 x 10(-5)) and TMEM2 (P = 7.75 x 10(-6)) whilst four were downregulated; ACVR1 (P = 9.01 x 10(-5)), NFATC2IP (P = 8.86 x 10(-5)), SUN1 (P = 3.87 x 10(-5)) and TTC9C (P = 7.18 x 10(-6)). These genes were also highly expressed in carotid atherosclerotic plaques. Conclusions We found seven genes involved in STEMI. The study is unique regarding the blood sampling in the acute phase and omission of secondary expressed genes from innate immunity. However, the results need to be replicated by future studies.
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- Bonomi, A, et al.
(author)
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Analysis of the genetic variants associated with circulating levels of sgp130. Results from the IMPROVE study
- 2020
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In: Genes and immunity. - : Springer Science and Business Media LLC. - 1476-5470 .- 1466-4879. ; 21:2, s. 100-108
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Journal article (peer-reviewed)abstract
- The genes regulating circulating levels of soluble gp130 (sgp130), the antagonist of the inflammatory response in atherosclerosis driven by interleukin 6, are largely unknown. Aims of the present study were to identify genetic loci associated with circulating sgp130 and to explore the potential association between variants associated with sgp130 and markers of subclinical atherosclerosis. The study is based on IMPROVE (n = 3703), a cardiovascular multicentre study designed to investigate the determinants of carotid intima media thickness, a measure of subclinical atherosclerosis. Genomic DNA was genotyped by the CardioMetaboChip and ImmunoChip. About 360,842 SNPs were tested for association with log-transformed sgp130, using linear regression adjusted for age, gender, and population stratification using PLINK v1.07. A p value of 1 × 10−5 was chosen as threshold for significance value. In an exploratory analysis, SNPs associated with sgp130 were tested for association with c-IMT measures. We identified two SNPs significantly associated with sgp130 levels and 24 showing suggestive association with sgp130 levels. One SNP (rs17688225) on chromosome 14 was positively associated with sgp130 serum levels (β = 0.03 SE = 0.007, p = 4.77 × 10−5) and inversely associated with c-IMT (c-IMTmean–maxβ = −0.001 SE = 0.005, p = 0.0342). Our data indicate that multiple loci regulate sgp130 levels and suggest a possible common pathway between sgp130 and c-IMT measures.
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- Li, D. Y., et al.
(author)
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H19 Induces Abdominal Aortic Aneurysm Development and Progression
- 2018
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In: Circulation. - : Ovid Technologies (Wolters Kluwer Health). - 0009-7322 .- 1524-4539. ; 138:15, s. 1551-1568
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Journal article (peer-reviewed)abstract
- Background: Long noncoding RNAs have emerged as critical molecular regulators in various biological processes and diseases. Here we sought to identify and functionally characterize long noncoding RNAs as potential mediators in abdominal aortic aneurysm development. Methods: We profiled RNA transcript expression in 2 murine abdominal aortic aneurysm models, Angiotensin II (ANGII) infusion in apolipoprotein E-deficient (ApoE(-/-)) mice (n=8) and porcine pancreatic elastase instillation in C57BL/6 wild-type mice (n=12). The long noncoding RNA H19 was identified as 1 of the most highly upregulated transcripts in both mouse aneurysm models compared with sham-operated controls. This was confirmed by quantitative reverse transcription-polymerase chain reaction and in situ hybridization. Results: Experimental knock-down of H19, utilizing site-specific antisense oligonucleotides (LNA-GapmeRs) in vivo, significantly limited aneurysm growth in both models. Upregulated H19 correlated with smooth muscle cell (SMC) content and SMC apoptosis in progressing aneurysms. Importantly, a similar pattern could be observed in human abdominal aortic aneurysm tissue samples, and in a novel preclinical LDLR-/- (low-density lipoprotein receptor) Yucatan mini-pig aneurysm model. In vitro knock-down of H19 markedly decreased apoptotic rates of cultured human aortic SMCs, whereas overexpression of H19 had the opposite effect. Notably, H19-dependent apoptosis mechanisms in SMCs appeared to be independent of miR-675, which is embedded in the first exon of the H19 gene. A customized transcription factor array identified hypoxia-inducible factor 1 as the main downstream effector. Increased SMC apoptosis was associated with cytoplasmic interaction between H19 and hypoxia-inducible factor 1 and sequential p53 stabilization. Additionally, H19 induced transcription of hypoxia-inducible factor 1 via recruiting the transcription factor specificity protein 1 to the promoter region. Conclusions: The long noncoding RNA H19 is a novel regulator of SMC survival in abdominal aortic aneurysm development and progression. Inhibition of H19 expression might serve as a novel molecular therapeutic target for aortic aneurysm disease.
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- Rykaczewska, U., et al.
(author)
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Plaque Evaluation by Ultrasound and Transcriptomics Reveals BCLAF1 as a Regulator of Smooth Muscle Cell Lipid Transdifferentiation in Atherosclerosis
- 2022
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In: Arteriosclerosis Thrombosis and Vascular Biology. - : Ovid Technologies (Wolters Kluwer Health). - 1079-5642 .- 1524-4636. ; 42:5, s. 659-676
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Journal article (peer-reviewed)abstract
- Background: Understanding the processes behind carotid plaque instability is necessary to develop methods for identification of patients and lesions with stroke risk. Here, we investigated molecular signatures in human plaques stratified by echogenicity as assessed by duplex ultrasound. Methods: Lesion echogenicity was correlated to microarray gene expression profiles from carotid endarterectomies (n=96). The findings were extended into studies of human and mouse atherosclerotic lesions in situ, followed by functional investigations in vitro in human carotid smooth muscle cells (SMCs). Results: Pathway analyses highlighted muscle differentiation, iron homeostasis, calcification, matrix organization, cell survival balance, and BCLAF1 (BCL2 [B-cell lymphoma 2]-associated transcription factor 1) as the most significant signatures. BCLAF1 was downregulated in echolucent plaques, positively correlated to proliferation and negatively to apoptosis. By immunohistochemistry, BCLAF1 was found in normal medial SMCs. It was repressed early during atherogenesis but reappeared in CD68+ cells in advanced plaques and interacted with BCL2 by proximity ligation assay. In cultured SMCs, BCLAF1 was induced by differentiation factors and mitogens and suppressed by macrophage-conditioned medium. BCLAF1 silencing led to downregulation of BCL2 and SMC markers, reduced proliferation, and increased apoptosis. Transdifferentiation of SMCs by oxLDL (oxidized low-denisty lipoprotein) was accompanied by upregulation of BCLAF1, CD36, and CD68, while oxLDL exposure with BCLAF1 silencing preserved MYH (myosin heavy chain) 11 expression and prevented transdifferentiation. BCLAF1 was associated with expression of cell differentiation, contractility, viability, and inflammatory genes, as well as the scavenger receptors CD36 and CD68. BCLAF1 expression in CD68+/BCL2+ cells of SMC origin was verified in plaques from MYH11 lineage-tracing atherosclerotic mice. Moreover, BCLAF1 downregulation associated with vulnerability parameters and cardiovascular risk in patients with carotid atherosclerosis. Conclusions: Plaque echogenicity correlated with enrichment of distinct molecular pathways and identified BCLAF1, previously not described in atherosclerosis, as the most significant gene. Functionally, BCLAF1 seems necessary for survival and transdifferentiation of SMCs into a macrophage-like phenotype. The role of BCLAF1 in plaque vulnerability should be further evaluated.
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- Castaldo, L, et al.
(author)
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Genetic Variants Associated with Non-Alcoholic Fatty Liver Disease Do Not Associate with Measures of Sub-Clinical Atherosclerosis: Results from the IMPROVE Study
- 2020
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In: Genes. - : MDPI AG. - 2073-4425. ; 11:11
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Journal article (peer-reviewed)abstract
- Non-alcoholic fatty liver disease (NAFLD) and atherosclerosis-related cardiovascular diseases (CVD) share common metabolic pathways. We explored the association between three NAFLD-associated single nucleotide polymorphisms (SNPs) rs738409, rs10401969, and rs1260326 with sub-clinical atherosclerosis estimated by the carotid intima-media thickness (c-IMT) and the inter-adventitia common carotid artery diameter (ICCAD) in patients free from clinically overt NAFLD and CVD. The study population is the IMPROVE, a multicenter European study (n = 3711). C-IMT measures and ICCAD were recorded using a standardized protocol. Linear regression with an additive genetic model was used to test for association of the three SNPs with c-IMT and ICCAD. In secondary analyses, the association of the three SNPs with c-IMT and ICCAD was tested after stratification by alanine aminotransferase levels (ALT). No associations were found between rs738409, rs1260326, rs10401969, and c-IMT or ICCAD. Rs738409-G and rs10401969-C were associated with ALT levels (p < 0.001). In patients with ALT levels above 28 U/L (highest quartile), we observed an association between rs10401969-C and c-IMT measures of c-IMTmax and c-IMTmean-max (p = 0.018 and 0.021, respectively). In conclusion, NAFLD-associated SNPs do not associate with sub-clinical atherosclerosis measures. However, our results suggest a possible mediating function of impaired liver function on atherosclerosis development.
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| 10. |
- Olofsson, P. S., et al.
(author)
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Genetic variants of TNFSF4 and risk for carotid artery disease and stroke
- 2009
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In: Journal of Molecular Medicine. - New York : Springer. - 0946-2716 .- 1432-1440. ; 87:4, s. 337-346
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Journal article (peer-reviewed)abstract
- In two independent human cohorts, the minor allele of SNP rs3850641 in TNFSF4 was significantly more frequent in individuals with myocardial infarction than in controls. In mice, Tnfsf4 expression is associated with increased atherosclerosis. The expression of TNFSF4 in human atherosclerosis and the association between genotype and cerebrovascular disease have not yet been investigated. TNFSF4 messenger RNA (mRNA) levels were significantly higher in human atherosclerotic lesions compared with controls (730∈±∈30 vs 330∈±∈65 arbitrary units, p∈<∈0.01). TNFSF4 was mainly expressed by macrophages in atherosclerotic lesions. In cell culture, endothelial cells upregulated TNFSF4 in response to tumor necrosis factor alpha (TNF-α; 460∈±∈110 vs 133∈±∈8 arbitrary units, p∈<∈0.001 after 6 h of stimulation). We analyzed the TNFSF4 gene in 239 patients who had undergone carotid endarterectomy and 138 matching controls from The Biobank of Karolinska Carotid Endarterectomies and Stockholm Heart Epidemiology Program cohorts and 929 patients and 1,382 matching controls from the Sahlgrenska Academy Study on Ischemic Stroke and Case Control Study of Stroke cohorts, limiting inclusion to patients with ischemic stroke. Participants were genotyped for the rs3850641 SNP in TNFSF4. Genotype associations were neither found with TNFSF4 mRNA levels nor with atherosclerosis associated systemic factors or risk for stroke. This study shows that TNFSF4 is expressed on antigen-presenting cells in human carotid atherosclerotic lesions but provides no evidence for an association of TNFSF4 gene variation with the risk for ischemic stroke.
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