Murine atherosclerosis models are key for investigation of atherosclerosis pathophysiology and drug development. However, they do not feature spontaneous atherothrombosis as a final stage of... Show moreMurine atherosclerosis models are key for investigation of atherosclerosis pathophysiology and drug development. However, they do not feature spontaneous atherothrombosis as a final stage of atherosclerosis. Transgenic mice expressing both the human mutant apolipoprotein E form APOE*3-Leiden and human cholesteryl ester transfer protein (CETP), i.e. APOE*3-Leiden.CETP mice, feature a moderate hyperlipoproteinemia and atherosclerosis phenotype. In contrast to apolipoprotein E deficient (Apoe(-/-)) mice, APOE*3-Leiden.CETP mice respond well to lipid-lowering and anti-atherosclerotic drugs. The aim of the study was to investigate whether silencing of anticoagulant Protein C (Proc) allows APOE*3-Leiden.CETP mice to feature thrombosis as a final stage of atherosclerosis. Female APOE*3-Leiden.CETP mice were fed a Western-type diet to induce advanced atherosclerosis, followed by an injection with a small interfering RNA targeting Proc (siProc). Presence of atherosclerosis and atherothrombosis was determined by histologic analysis of the aortic root. Atherosclerosis severity in the aortic root area of APOE*3-Leiden.CETP mice varied from type "0" (no lesions) to type "V" lesions (advanced and complex lesions). Atherothrombosis following siProc injection was observed for 4 out of 21 APOE*3-Leiden.CETP mice (19% incidence). The atherothrombosis presented as large, organized, fibrin- and leukocyte-rich thrombi on top of advanced (type "V") atherosclerotic plaques in the aortic root. This atherothrombosis was comparable in appearance and incidence as previously reported for Apoe(-/-) mice with a more severe atherosclerosis (19% incidence). APOE*3-Leiden.CETP mice with modest hyperlipidemia and atherosclerosis can develop atherothrombosis upon transient Proc-silencing. This further extends the use of these mice as a test model for lipid-lowering and anti-atherosclerotic drugs. Show less
Aims Brown fat activation accelerates the uptake of cholesterol-enriched remnants by the liver and thereby lowers plasma cholesterol, consequently protecting against atherosclerosis development.... Show moreAims Brown fat activation accelerates the uptake of cholesterol-enriched remnants by the liver and thereby lowers plasma cholesterol, consequently protecting against atherosclerosis development. Hepatic cholesterol is then converted into bile acids (BAs) that are secreted into the intestine and largely maintained within the enterohepatic circulation. We now aimed to evaluate the effects of prolonged brown fat activation combined with inhibition of intestinal BA reabsorption on plasma cholesterol metabolism and atherosclerosis development.Methods and results APOE*3-Leiden.CETP mice with humanized lipoprotein metabolism were treated for 9 weeks with the selective beta 3-adrenergic receptor (AR) agonist CL316,243 to substantially activate brown fat. Prolonged beta 3-AR agonism reduced faecal BA excretion (-31%), while markedly increasing plasma levels of total BAs (+258%), cholic acid-derived BAs (+295%), and chenodeoxycholic acid-derived BAs (+217%), and decreasing the expression of hepatic genes involved in BA production. In subsequent experiments, mice were additionally treated with the BA sequestrant Colesevelam to inhibit BA reabsorption. Concomitant intestinal BA sequestration increased faecal BA excretion, normalized plasma BA levels, and reduced hepatic cholesterol. Moreover, concomitant BA sequestration further reduced plasma total cholesterol (-49%) and non-high-density lipoprotein cholesterol (-56%), tended to further attenuate atherosclerotic lesion area (-54%). Concomitant BA sequestration further increased the proportion of lesion-free valves (+34%) and decreased the relative macrophage area within the lesion (-26%), thereby further increasing the plaque stability index (+44%).Conclusion BA sequestration prevents the marked accumulation of plasma BAs as induced by prolonged brown fat activation, thereby further improving cholesterol metabolism and reducing atherosclerosis development. These data suggest that combining brown fat activation with BA sequestration is a promising new therapeutic strategy to reduce hyperlipidaemia and cardiovascular diseases. Show less
Thiem, K.; Hoeke, G.; Zhou, E.C.; Hijmans, A.; Houben, T.; Boels, M.G.; ... ; Diepen, J.A. van 2019
Background: C-type lectin receptors, including Dectin-2, are pattern recognition receptors on monocytes and macrophages that mainly recognize sugars and sugar-like structures present on fungi.... Show moreBackground: C-type lectin receptors, including Dectin-2, are pattern recognition receptors on monocytes and macrophages that mainly recognize sugars and sugar-like structures present on fungi. Activation of C-type lectin receptors induces downstream CARD9 signalling, leading to the production of cytokines. We hypothesized that under hyperglycaemic conditions, as is the case in diabetes mellitus, glycosylated protein (sugar-like) structures activate C-type lectin receptors, leading to immune cell activation and increased atherosclerosis development. Methods: Low-density lipoprotein receptor-deficient mice were lethally irradiated and transplanted with bone marrow from control wild-type, Dectin-2(-/-) or Card9(-/-) mice. After 6 weeks of recovery, mice received streptozotocin injections (50 mg/g BW; 5 days) to induce hyperglycaemia. After an additional 2 weeks, mice were fed a Western-type diet (0.1% cholesterol) for 10 weeks. Results and Conclusion: Deletion of haematopoietic Dectin-2 reduced the number of circulating Ly6C(hi) monocytes, increased pro-inflammatory cytokine production, but did not affect atherosclerosis development. Deletion of haematopoietic CARD9 tended to reduce macrophage and collagen content in atherosclerotic lesions, again without influencing the lesion size. Deletion of haematopoietic Dectin-2 did not influence atherosclerosis development under hyperglycaemic conditions, despite some minor effects on inflammation. Deletion of haematopoietic CARD9 induced minor alterations in plaque composition under hyperglycaemic conditions, without affecting lesion size. Show less
Conclusions: BCG reduces plasma nonHDL-cholesterol levels and delays atherosclerotic lesion formation in hyperlipidemic mice. (C) 2016 The Authors. Published by Elsevier Ireland Ltd. This is an... Show moreConclusions: BCG reduces plasma nonHDL-cholesterol levels and delays atherosclerotic lesion formation in hyperlipidemic mice. (C) 2016 The Authors. Published by Elsevier Ireland Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Show less
