| 1. |
- Edsfeldt, Andreas, et al.
(författare)
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Transforming growth factor-β2 is associated with atherosclerotic plaque stability and lower risk for cardiovascular events
- 2023
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Ingår i: Cardiovascular Research. - : Oxford University Press. - 0008-6363 .- 1755-3245. ; 119:11, s. 2061-2073
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Tidskriftsartikel (refereegranskat)abstract
- Aims: Transforming growth factor-beta (TGF-β) exists in three isoforms TGF-β1, -β2, and -β3. TGF-β1 has been suggested to be important for maintaining plaque stability, yet the role of TGF-β2 and -β3 in atherosclerosis remains to be investigated. This study explores the association of the three isoforms of TGF-β with plaque stability in the human atherosclerotic disease. Methods and results: TGF-β1, -β2, and -β3 proteins were quantified in 223 human carotid plaques by immunoassays. Indications for the endarterectomy were: symptomatic carotid plaque with stenosis >70% or without symptoms and >80% stenosis. Plaque mRNA levels were assessed by RNA sequencing. Plaque components and extracellular matrix were measured histologically and biochemically. Matrix metalloproteinases and monocyte chemoattractant protein-1 (MCP-1) was measured with immunoassays. The effect of TGF-β2 on inflammation and protease activity was investigated in vitro using THP-1 and RAW264.7 macrophages. Patients were followed longitudinally for cardiovascular (CV) events. TGF-β2 was the most abundant isoform and was increased at both protein and mRNA levels in asymptomatic plaques. TGF-β2 was the main determinant separating asymptomatic plaques in an Orthogonal Projections to Latent Structures Discriminant Analysis. TGF-β2 correlated positively to features of plaque stability and inversely to markers of plaque vulnerability. TGF-β2 was the only isoform inversely correlated to the matrix-degrading matrix metalloproteinase-9 and inflammation in the plaque tissue. In vitro, TGF-β2 pre-treatment reduced MCP-1 gene and protein levels as well as matrix metalloproteinase-9 gene levels and activity. Patients with plaques with high TGF-β2 levels had a lower risk to suffer from future CV events. Conclusions: TGF-β2 is the most abundant TGF-β isoform in human plaques and may maintain plaque stability by decreasing inflammation and matrix degradation.
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| 2. |
- Forteza, Maria J., et al.
(författare)
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Pyruvate dehydrogenase kinase regulates vascular inflammation in atherosclerosis and increases cardiovascular risk
- 2023
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Ingår i: Cardiovascular Research. - : Oxford University Press (OUP). - 0008-6363 .- 1755-3245. ; 119:7, s. 1524-1536
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Tidskriftsartikel (refereegranskat)abstract
- Recent studies have revealed a close connection between cellular metabolism and the chronic inflammatory process of atherosclerosis. While the link between systemic metabolism and atherosclerosis is well established, the implications of altered metabolism in the artery wall are less understood. Pyruvate dehydrogenase kinase (PDK)-dependent inhibition of pyruvate dehydrogenase (PDH) has been identified as a major metabolic step regulating inflammation. Whether the PDK/PDH axis plays a role in vascular inflammation and atherosclerotic cardiovascular disease remains unclear. Methods and results Gene profiling of human atherosclerotic plaques revealed a strong correlation between PDK1 and PDK4 transcript levels and the expression of pro-inflammatory and destabilizing genes. Remarkably, the PDK1 and PDK4 expression correlated with a more vulnerable plaque phenotype, and PDK1 expression was found to predict future major adverse cardiovascular events. Using the small-molecule PDK inhibitor dichloroacetate (DCA) that restores arterial PDH activity, we demonstrated that the PDK/PDH axis is a major immunometabolic pathway, regulating immune cell polarization, plaque development, and fibrous cap formation in Apoe−/− mice. Surprisingly, we discovered that DCA regulates succinate release and mitigates its GPR91-dependent signals promoting NLRP3 inflammasome activation and IL-1β secretion by macrophages in the plaque. Conclusions We have demonstrated for the first time that the PDK/PDH axis is associated with vascular inflammation in humans and particularly that the PDK1 isozyme is associated with more severe disease and could predict secondary cardiovascular events. Moreover, we demonstrate that targeting the PDK/PDH axis with DCA skews the immune system, inhibits vascular inflammation and atherogenesis, and promotes plaque stability features in Apoe−/− mice. These results point toward a promising treatment to combat atherosclerosis.
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| 3. |
- Gisterå, Anton
(författare)
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T-cell specificity and regulation in atherosclerosis
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Cardiovascular disease is the main cause of death in the world. The underlying cause in most cases is atherosclerosis, a chronic inflammatory disease. Subendothelial retention of lipoproteins triggers monocyte-derived macrophages and T-helper (Th) 1 cells to form lipid-laden atherosclerotic plaques in the artery wall. The Th1 cells react to autoantigens from the ApoB protein in low-density lipoprotein (LDL) perpetuating the inflammation initiated by the innate immune reactions to modified lipoproteins. Other T-helper cells are also active in the lesions with regulatory T cells (Treg) limiting the injurious inflammation, while the effects of Th17 cells are less clear. The slow build-up of atherosclerotic plaques is asymptomatic, but eventually the plaque may cause symptoms. Plaque rupture or endothelial erosion induces thrombus formation that causes a heart attack or ischemic stroke. Advanced plaques usually contain large cholesterol-rich necrotic cores. This determines plaque stability along with a stable cap formation by smooth muscle cells and collagen. Prevention of risk factors has reduced mortality, but there is still a need for novel therapies to stabilize plaques and to treat arterial inflammation. The aim for this thesis is to investigate T-cell responses to LDL and regulation of Th cells during atherogenesis. Genetically modified mouse models were used to study LDL-reactive T cells, mechanisms involved in Th cell differentiation, and the subsequent influence on disease development. Paper I shows how inflammatory signals from the atherosclerotic lesions contribute to Th17 cell differentiation by means of IL-6 and transforming growth factor β (TGF-β). Th17 cells produce IL-17A that promotes collagen synthesis by smooth muscle cells. This paper establishes a plaque-stabilizing role for Th17 cells and IL-17A, which is likely to operate in man and reduce incidence of myocardial infarctions. Paper II establishes that Tregs have a protective role in atherosclerosis by modulating lipid metabolism. Depletion of Foxp3+ Tregs during atherogenesis impairs lipoprotein uptake by unleashing liver inflammation that downregulates the very low-density lipoprotein (VLDL)-regulating protein called sortilin. This leads to increased plasma cholesterol and development of large atherosclerotic plaques with lipid-filled necrotic cores. Paper III shows how LDL-reactive T cells survive clonal selection in the thymus, differentiate into T follicular helper cells (Tfh), and promote a protective B-cell response with anti-LDL antibodies. These antibodies mediate lipoprotein clearance and lower plasma cholesterol, which protects against atherosclerosis. All three papers presented in this thesis illustrate an intricate interplay between the immune system and lipoprotein metabolism, resulting in profound effects on atherosclerosis. These notions may lead to new therapies that stabilize atherosclerotic plaques through specific anti-inflammatory actions that are mirrored by lipid-lowering effects.
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| 4. |
- Klingenberg, Roland, et al.
(författare)
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Depletion of FOXP3(+) regulatory T cells promotes hypercholesterolemia and atherosclerosis
- 2013
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Ingår i: Journal of Clinical Investigation. - 0021-9738 .- 1558-8238. ; 123:3, s. 1323-1334
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Tidskriftsartikel (refereegranskat)abstract
- Atherosclerosis is a chronic inflammatory disease promoted by hyperlipidemia. Several studies support FOXP3-positive regulatory T cells (Tregs) as inhibitors of atherosclerosis; however, the mechanism underlying this protection remains elusive. To define the role of FOXP3-expressing Tregs in atherosclerosis, we used the DEREG mouse, which expresses the diphtheria toxin (DT) receptor under control of the Treg-specific Foxp3 promoter, allowing for specific ablation of FOXP3(+) Tregs. Lethally irradiated, atherosclerosis-prone, low-density lipoprotein receptor-deficient (Ldlr(-/-)) mice received DEREG bone marrow and were injected with DT to eliminate FOXP3(+) Tregs. Depletion of Tregs caused a 2.1-fold increase in atherosclerosis without a concomitant increase in vascular inflammation. These mice also exhibited a 1.7-fold increase in plasma cholesterol and an atherogenic lipoprotein profile with increased levels of VLDL. Clearance of VLDL and chylomicron remnants was hampered, leading to accumulation of cholesterol-rich particles in the circulation. Functional and protein analyses complemented by gene expression array identified reduced protein expression of sortilin-1 in liver and increased plasma enzyme activity of lipoprotein lipase, hepatic lipase, and phospholipid transfer protein as mediators of the altered lipid phenotype. These results demonstrate that FOXP3(+) Tregs inhibit atherosclerosis by modulating lipoprotein metabolism.
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| 5. |
- Kumawat, Ashok Kumar, 1982-, et al.
(författare)
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Inhibition of IL17A Using an Affibody Molecule Attenuates Inflammation in ApoE-Deficient Mice
- 2022
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Ingår i: Frontiers in Cardiovascular Medicine. - : Frontiers Media S.A.. - 2297-055X. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- The balance between pro- and anti-inflammatory cytokines released by immune and non-immune cells plays a decisive role in the progression of atherosclerosis. Interleukin (IL)-17A has been shown to accelerate atherosclerosis. In this study, we investigated the effect on pro-inflammatory mediators and atherosclerosis development of an Affibody molecule that targets IL17A. Affibody molecule neutralizing IL17A, or sham were administered in vitro to human aortic smooth muscle cells (HAoSMCs) and murine NIH/3T3 fibroblasts and in vivo to atherosclerosis-prone, hyperlipidaemic ApoE(-/-) mice. Levels of mediators of inflammation and development of atherosclerosis were compared between treatments. Exposure of human smooth muscle cells and murine NIH/3T3 fibroblasts in vitro to alpha IL-17A Affibody molecule markedly reduced IL6 and CXCL1 release in supernatants compared with sham exposure. Treatment of ApoE(-/-) mice with alpha IL-17A Affibody molecule significantly reduced plasma protein levels of CXCL1, CCL2, CCL3, HGF, PDGFB, MAP2K6, QDPR, and splenocyte mRNA levels of Ccxl1, Il6, and Ccl20 compared with sham exposure. There was no significant difference in atherosclerosis burden between the groups. In conclusion, administration of alpha IL17A Affibody molecule reduced levels of pro-inflammatory mediators and attenuated inflammation in ApoE(-/-) mice.
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| 6. |
- Söderström, Leif, et al.
(författare)
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Increased carotid artery lesion inflammation upon treatment with the CD137 agonistic antibody 2A
- 2017
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Ingår i: Circulation Journal. - 1346-9843. ; 81:12, s. 1945-1952
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Tidskriftsartikel (refereegranskat)abstract
- Background: Increased inflammatory activity destabilizes the atherosclerotic lesion and may lead to atherothrombosis and symptomatic cardiovascular disease. Co-stimulatory molecules, such as CD137, are key regulators of inflammation, and CD137 activity regulates inflammation in experimental atherosclerosis. Here, we hypothesized that CD137 activation promotes carotid artery inflammation and atherothrombosis. Methods and Results: In a model of inducible atherothrombosis with surgical ligation of the right carotid artery and a subsequent placement of a polyethene cuff, elevated levels of CD137 and CD137 ligand mRNA in atherothrombotic vs. non-atherothrombotic murine carotid lesions was observed. Mice treated with the CD137 agonistic antibody 2A showed signs of increased inflammation in the aorta and a higher proportion of CD8+ T cells in spleen and blood. In carotid lesions of 2A-treated mice, significantly higher counts of CD8+ and major histocompatibility (MHC)-class II molecule I-Ab+ cells were observed. Treatment with the CD137 agonistic antibody 2A did not significantly affect the atherothrombosis frequency in 16-week-old mice in this model. Conclusions: Levels of CD137 and CD137 ligand mRNA were higher in advanced atherosclerotic disease compared to control vessels, and treatment with the CD137 agonistic antibody 2A, in a murine model for inducible atherothrombosis promoted vascular inflammation, but had no significant effect on atherothrombosis frequency at this early disease stage.
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