Background The association between triglyceride glucose (TyG) index and coronary atherosclerotic change remains unclear. We aimed to evaluate the association between TyG index and coronary plaque... Show moreBackground The association between triglyceride glucose (TyG) index and coronary atherosclerotic change remains unclear. We aimed to evaluate the association between TyG index and coronary plaque progression (PP) using serial coronary computed tomography angiography (CCTA). Methods A total of 1143 subjects (aged 60.7 +/- 9.3 years, 54.6% male) who underwent serial CCTA with available data on TyG index and diabetic status were analyzed from The Progression of AtheRosclerotic PlAque DetermIned by Computed TomoGraphic Angiography IMaging (PARADIGM) registry. PP was defined as plaque volume (PV) (mm(3)) at follow-up minus PV at index > 0. Annual change of PV (mm(3)/year) was defined as PV change divided by inter-scan period. Rapid PP was defined as the progression of percent atheroma volume (PV divided by vessel volume multiplied by 100) >= 1.0%/year. Results The median inter-scan period was 3.2 (range 2.6-4.4) years. All participants were stratified into three groups based on TyG index tertiles. The overall incidence of PP was 77.3%. Baseline total PV (group I [lowest]: 30.8 (0.0-117.7), group II: 47.2 (6.2-160.4), and group III [highest]: 57.5 (8.4-154.3); P < 0.001) and the annual change of total PV (group I: 5.7 (0.0-20.2), group II: 7.6 (0.5-23.5), and group III: 9.4 (1.4-27.7); P = 0.010) were different among all groups. The risk of PP (odds ratio [OR] 1.648; 95% confidence interval [CI] 1.167-2.327; P = 0.005) and rapid PP (OR 1.777; 95% CI 1.288-2.451; P < 0.001) was increased in group III compared to that in group I. TyG index had a positive and significant association with an increased risk of PP and rapid PP after adjusting for confounding factors. Conclusion TyG index is an independent predictive marker for the progression of coronary atherosclerosis. Clinical registrationClinicalTrials.gov NCT02803411 Show less
Ferro, D.; Brink, H. van den; Amier, R.; Buchem, M. van; Bresser, J. de; Bron, E.; ... ; Heart-Brain Connection Consortium 2020
Background: Patients with heart failure (HF) are at risk for vascular brain injury. Cerebral cortical microinfarcts (CMIs) are a novel MRI marker of vascular brain injury. This study aims to... Show moreBackground: Patients with heart failure (HF) are at risk for vascular brain injury. Cerebral cortical microinfarcts (CMIs) are a novel MRI marker of vascular brain injury. This study aims to determine the occurrence of CMIs in patient with HF and their clinical correlates, including haemodynamic status.Methods: From the Heart-Brain Study, a multicenter prospective cohort study, 154 patients with clinically stable HF without concurrent atrial fibrillation (mean age 69.5 +/- 10.1, 32% female) and 124 reference participants without HF (mean age 65.6 +/- 7.4, 47% females) were evaluated for CMIs on 3 T MRI. CMI presence in HF was tested for associations with vascular risk profile, cardiac function and history, MRI markers of vascular brain injury and cognitive profile.Results: CMI occurrence was higher in patient with HF (17%) than reference participants (7%); after correction for age and sex OR 2.5 [95% CI 1.1-6.0] p=.032; after additional correction for vascular risk factors OR 2.7 [1.0-7.1] p=.052. In patients with HF, CMI presence was associated with office hypertension (OR 2.7 [1.2-6.5] p =.021) and a lower cardiac index (B = -0.29 [-0.55--0.04] p =.023 independent of vascular risk factors), but not with cause or duration of HF. Presence of CMIs was not associated with cognitive performance in patients with HF.Conclusions: CMIs are a common occurrence in patients with HF and related to an adverse vascular risk factor profile and severity of cardiac dysfunction. CMIs thus represent a novel marker of vascular brain injury in these patients. (c) 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Show less
Despite the available treatment options and sophisticated imaging technologies for monitoring lesion development, the morbidity and mortality from acute cardiovascular events remain unacceptably... Show moreDespite the available treatment options and sophisticated imaging technologies for monitoring lesion development, the morbidity and mortality from acute cardiovascular events remain unacceptably high.While cholesterol-lowering, anti-inflammatory and anti-platelet therapies benefits can increase survival as a primary or secondary prevention, they are not sufficient for plaque rupture prevention. Moreover, the most advance imaging technologies to detect high-risk atherosclerotic patients fail to visualize and explore cellular events in small preclinical models. Therefore, there is a clear need for the development of new therapies and the application of high-resolution imaging modalities.In the current thesis, we evaluated new possibilities to inhibit and image intraplaque angiogenesis. Show less
Kishi, S.; Magalhaes, T.A.; Cerci, R.J.; Zimmermann, E.; Matheson, M.B.; Vavere, A.; ... ; Arbab-Zadeh, A. 2020
Purpose To provide comparative prognostic information of coronary atherosclerotic plaque volume and stenosis assessment in patients with suspected coronary artery disease (CAD). Methods We followed... Show morePurpose To provide comparative prognostic information of coronary atherosclerotic plaque volume and stenosis assessment in patients with suspected coronary artery disease (CAD). Methods We followed 372 patients with suspected or known CAD enrolled in the CORE320 study for 2 years after baseline 320-detector row cardiac CT scanning and invasive quantitative coronary angiography (QCA). CT images were analyzed for coronary calcium scanning (CACS), semi-automatically derived total percent atheroma volume (PAV), segment stenosis score (SSS), in addition to traditional stenosis assessment (>= 50%) by CT and QCA for (1) 30-day revascularization and (2) major adverse cardiac events (MACE). Area under the receiver operating characteristic curve (AUC) was used to compare accuracy of risk prediction. Results Sixty percent of patients had obstructive CAD by QCA with 23% undergoing 30-day revascularization and 9% experiencing MACE at 2 years. Most late events (20/32) were revascularization procedures. Prediction of 30-day revascularization was modest (AUC range 0.67-0.78) but improved after excluding patients with known CAD (AUC range 0.73-0.86, p < 0.05 for all). Similarly, prediction of MACE improved after excluding patients with known CAD (AUC range 0.58-0.73 vs. 0.63-0.77). CT metrics of atherosclerosis burden performed overall similarly but stenosis assessment was superior for predicting 30-day revascularization. Conclusions Angiographic and coronary atherosclerotic plaque metrics perform only modestly well for predicting 30-day revascularization and 2-year MACE in high risk patients but improve after excluding patients with known CAD. Atherosclerotic plaque metrics did not yield incremental value over stenosis assessment for predicting events that predominantly consisted of revascularization procedures. Show less
Background and aims: Neuroimmune guidance cues have been shown to play a role in atherosclerosis, but their exact role in human pathophysiology is largely unknown. In the current study, we... Show moreBackground and aims: Neuroimmune guidance cues have been shown to play a role in atherosclerosis, but their exact role in human pathophysiology is largely unknown. In the current study, we investigated the role of a c.1769G > T variant in Netrin-1 in (premature) atherosclerosis.Methods: To determine the effect of the genetic variation, purified Netrin-1, either wild type (wtNetrin-1) or the patient observed variation (mutNetrin-1), was used for migration, adhesion, endothelial barrier function and bindings assays. Expression of adhesion molecules and transcription proteins was analyzed by RT-PCR, Western blot or ELISA. To further delineate how mutNetrin-1 mediates its effect on cell migration, lenti-viral knockdown of UNC5B or DCC was used.Results: Bindings assays revealed a decreased binding capacity of mutNetrin-1 to the receptors UNC5B, DCC and beta 3-integrin and an increased binding capacity to neogenin, heparin and heparan sulfate compared to wtNetrin-1. Exposure of endothelial cells to mutNetrin-1 resulted in enhanced monocyte adhesion and expression of IL-6, CCL2 and ICAM-1 compared to wtNetrin-1. In addition, mutNetrin-1 lacks the inhibitory effect on the NF-kappa B pathway that is observed for wtNetrin-1. Moreover, the presence of mutNetrin-1 diminished migration of macrophages and smooth muscle cells. Importantly, UNC5B or DCC specific knockdown showed that mutNetrin-1 is unable to act through DCC resulting in enhanced inhibition of migration.Conclusions: Our data demonstrates that mutNetrin-1 fails to exert anti-inflammatory effects on endothelial cells and more strongly blocks macrophage migration compared to wtNetrin-1, suggesting that the carriers of this genetic molecular variant may well be at risk for premature atherosclerosis. Show less
Atherosclerosis is the most important underlying process that drives cardiovascular disease, and is characterized by an accumulation of cholesterol which triggers an inflammatory response in the... Show moreAtherosclerosis is the most important underlying process that drives cardiovascular disease, and is characterized by an accumulation of cholesterol which triggers an inflammatory response in the vessel wall. This results in the recruitment of many types of inflammatory cells towards the plaques that form in the vessel wall, among which are CD8+ T-cells. In this thesis, the role of CD8+ T-cells in the advanced stages of lesion development has been investigated, as this is the most clinically relevant stage of the disease. This thesis demonstrates that CD8+ T-cells exert a protective function. We show that the absence of CD8+ T-cells in a mouse model results in less stable atherosclerotic lesions with increased numbers of inflammatory cells. In a subsequent study, we show that CD8+ T-cells express an enzyme that inhibits the inflammatory process. We also show that injecting a specific subset of CD8+ T-cells is protective against the development of atherosclerotic lesions in mice. Importantly, we show that this data can be translated to atherosclerosis development in humans, as we demonstrate similar results using patient material obtained from endarterectomy surgery. Finally, we show that developing therapies directed towards activating CD8+ T-cells may be of value to inhibit the immune response, and thus reduce the risk of cardiovascular disease. Show less
Atherosclerosis is characterized by the retention of lipids in foam cells in the arterial intima. The liver X receptor (LXR) agonist GW3965 is a promising therapeutic compound, since it induces... Show moreAtherosclerosis is characterized by the retention of lipids in foam cells in the arterial intima. The liver X receptor (LXR) agonist GW3965 is a promising therapeutic compound, since it induces reverse cholesterol transport in foam cells. However, hepatic LXR activation increases plasma and liver lipid levels, inhibiting its clinical development. Herein, a formulation that specifically enhances GW3965 deposition in the atherosclerotic lesion is aimed to be developed. GW3965 is encapsulated in liposomes functionalized with the cyclic peptide Lyp-1 (CGNKRTRGC), which binds the p32 receptor expressed on foam cells. These liposomes show preferential uptake by foam cells in vitro and higher accumulation in atherosclerotic plaques in mice compared to non-targeted liposomes as determined by in vivo imaging. Flow cytometry analysis of plaques reveals increased retention of Lyp-1 liposomes in atherosclerotic plaque macrophages compared to controls (p < 0.05). Long term treatment of established plaques in LDLR -/- mice with GW3965-containing Lyp-1 liposomes significantly reduces plaque macrophage content by 50% (p < 0.01). Importantly, GW3965-containing Lyp-1 liposomes do not increase plasma or hepatic lipid content. Thus, GW3965-containing Lyp-1 liposomes successfully target the atherosclerotic macrophages allowing plaque stabilization without commonly observed side effects of LXR agonists. Show less
The thesis discussed several strategies that may contribute to further CVD risk reduction in the future. We described two novel lipid-lowering strategies, we unraveled (part of) the etiology of the... Show moreThe thesis discussed several strategies that may contribute to further CVD risk reduction in the future. We described two novel lipid-lowering strategies, we unraveled (part of) the etiology of the cardiovascular safety issues of TKIs that are used for the treatment of CML, and we investigated the dose effects of PFOA on lipoprotein metabolism. Looking forward, we developed a novel mouse model that can be used for the study of diabetic macrovascular complications, and we evaluated the potential of OSM as novel target in CVD. 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
Cardiovascular diseases are the primary cause of death in the world with atherosclerosis as primary underlying cause. Atherosclerosis is characterized by cholesterol accumulation in the vessel wall... Show moreCardiovascular diseases are the primary cause of death in the world with atherosclerosis as primary underlying cause. Atherosclerosis is characterized by cholesterol accumulation in the vessel wall and inflammation of the vessel wall of medium to large size arteries. Both cholesterol accumulation and inflammation are pathogenic in the context of atherosclerosis. Current treatment regimens are tailored to reduce cholesterol levels in the blood. However, even a successful lowering of cholesterol is in many patients not sufficient to prevent a major cardiovascular event due to unresolved inflammation. Therefore, the immune system provides an interesting therapeutic target for the treatment of atherosclerosis. In this thesis we have explored the effect on atherosclerosis of several immunomodulatory strategies in pre-clinical models.As cholesterol is not soluble in water, cholesterol is transported in the bloodstream in particles called lipoproteins. The low-density lipoprotein (LDL) carries the highest concentration of cholesterol and accumulates in the vessel wall where a pathogenic specific immune response against LDL is instigated. In this thesis we have used several strategies to modulate the specific immune response against LDL, inducing LDL-specific regulatory T cells, antibodies, and cytotoxic T cells. Through immunoproteasomal inhibition we assessed the effect of general immune inhibition on atherosclerosis. Show less
This thesis explores different avenues to develop insurmountable antagonists for CC Chemokine Receptors, such as CCR1, CCR2 and CCR5. These receptors, which belong to the large family of G protein... Show moreThis thesis explores different avenues to develop insurmountable antagonists for CC Chemokine Receptors, such as CCR1, CCR2 and CCR5. These receptors, which belong to the large family of G protein-coupled receptors (GPCRs), are implicated in a variety of inflammatory and immune diseases, including atherosclerosis, rheumatoid arthritis and cancer. Thus, numerous drug candidates have been developed over the years to target them. Despite promising preclinical data, most of these candidates have failed in clinical trials due to lack of efficacy, making necessary the development of novel tools and concepts to better study and target these receptors. Thus, throughout this thesis we have explored different mechanisms to achieve insurmountable inhibition, which include intracellular allosteric modulation, covalent inhibition and long residence time. Moreover, the crystal structure presented in this thesis provides a new template for the rational design of future antagonists. Finally, with the identification of several selective or multitarget intracellular ligands for CCR1, CCR2 and CCR5, we are expanding the toolbox to further modulate chemokine receptors. Overall, the results of this thesis may contribute to the development of novel chemokine receptor antagonists, and GPCRs in general, with improved in vivo efficacy. Show less
BACKGROUND: South Asians are more prone to develop atherosclerotic cardiovascular disease (ASCVD) compared with white Caucasians, which is not fully explained by classical risk factors. We recently... Show moreBACKGROUND: South Asians are more prone to develop atherosclerotic cardiovascular disease (ASCVD) compared with white Caucasians, which is not fully explained by classical risk factors. We recently reported that the presence of aggregation-prone low-density lipoprotein (LDL) in the circulation is associated with increased ASCVD mortality.OBJECTIVE: We hypothesized that LDL of South Asians is more prone to aggregate, which may be explained by differences in their LDL lipid composition.METHODS: In this cross-sectional hypothesis-generating study, LDL was isolated from plasma of healthy South Asians (n = 12) and age- and BMI-matched white Caucasians (n = 12), and its aggregation susceptibility and lipid composition were analyzed.RESULTS: LDL from South Asians was markedly more prone to aggregate compared with white Caucasians. Among all measured lipids, sphingomyelin 24:0 and triacylglycerol 56:8 showed the highest positive correlation with LDL aggregation. In addition, LDL from South Asians was enriched in arachidonic acid containing phosphatidylcholine 38:4 and had less phosphatidylcholines and cholesteryl esters containing monounsaturated fatty acids. Interestingly, body fat percentage, which was higher in South Asians (+26%), positively correlated with LDL aggregation and highly positively correlated with triacylglycerol 56:8, sphingomyelin 24:0, and total sphingomyelin.CONCLUSIONS: LDL aggregation susceptibility is higher in healthy young South Asians compared with white Caucasians. This may be partly explained by the higher body fat percentage of South Asians, leading to sphingomyelin enrichment of LDL. We anticipate that the presence of sphingomyelin-rich, aggregation -prone LDL particles in young South Asians may increase LDL accumulation in the arterial wall and thereby contribute to their increased risk of developing ASCVD later in life. (C) 2019 National Lipid Association. Published by Elsevier Inc. Show less
Dijk, L.J.D. van; Harki, J.; Noord, D. van; Verhagen, H.J.M.; Kolkman, J.J.; Geelkerken, R.H.; ... ; Dutch Mesenteric Ischemia Study Gr 2019
Background: Chronic mesenteric ischemia (CMI) is the result of insufficient blood supply to the gastrointestinal tract and is caused by atherosclerotic stenosis of one or more mesenteric arteries... Show moreBackground: Chronic mesenteric ischemia (CMI) is the result of insufficient blood supply to the gastrointestinal tract and is caused by atherosclerotic stenosis of one or more mesenteric arteries in > 90% of cases. Revascularization therapy is indicated in patients with a diagnosis of atherosclerotic CMI to relieve symptoms and to prevent acute-on-chronic mesenteric ischemia, which is associated with high morbidity and mortality. Endovascular therapy has rapidly evolved and has replaced surgery as the first choice of treatment in CMI. Bare-metal stents (BMS) are standard care currently, although retrospective studies suggested significantly higher patency rates for covered stents (CS). The Covered stents versus Bare-metal stents in chronic atherosclerotic Gastrointestinal Ischemia (CoBaGI) trial is designed to prospectively assess the patency of CS versus BMS in patients with atherosclerotic CMI.Methods/design: The CoBaGI trial is a randomized controlled, parallel-group, patient-and investigator-blinded, superiority, multicenter trial conducted in six centers of the Dutch Mesenteric Ischemia Study group (DMIS). Eighty-four patients with a consensus diagnosis of atherosclerotic CMI are 1:1 randomized to either a balloon-expandable BMS (Palmaz Blue with rapid-exchange delivery system, Cordis Corporation, Bridgewater, NJ, USA) or a balloon-expandable CS (Advanta V12 over-the-wire, Atrium Maquet Getinge Group, Hudson, NH, USA). The primary endpoint is the primary stent-patency rate at 24 months assessed with CT angiography. Secondary endpoints are primary stent patency at 6 and 12 months and secondary patency rates, freedom from restenosis, freedom from symptom recurrence, freedom from re-intervention, quality of life according the EQ-5D-5 L and SF-36 and cost-effectiveness at 6, 12 and 24 months.Discussion: The CoBaGI trial is designed to assess the patency rates of CS versus BMS in patients treated for CMI caused by atherosclerotic mesenteric stenosis. Furthermore, the CoBaGI trial should provide insights in the quality of life of these patients before and after stenting and its cost-effectiveness. The CoBaGI trial is the first randomized controlled trial performed in CMI caused by atherosclerotic mesenteric artery stenosis. Show less
Christen, T.; Trompet, S.; Rensen, P.C.N.; Dijk, K.W. van; Lamb, H.J.; Jukema, J.W.; ... ; Mutsert, R. de 2019
Mast cells are pluripotent leukocytes that reside in the mucosa and connective tissue. Recent studies show an increased prevalence of cardiovascular disease among patients with mastocytosis, which... Show moreMast cells are pluripotent leukocytes that reside in the mucosa and connective tissue. Recent studies show an increased prevalence of cardiovascular disease among patients with mastocytosis, which is a hematological disease that is characterized by the accumulation of mast cells due to clonal proliferation. This association suggests an important role for mast cells in cardiovascular disease. Indeed, the evidence establishing the contribution of mast cells to the development and progression of atherosclerosis is continually increasing. Mast cells may contribute to plaque formation by stimulating the formation of foam cells and causing a pro-inflammatory micro-environment. In addition, these cells are able to promote plaque instability by neo-vessel formation and also by inducing intraplaque hemorrhage. Furthermore, mast cells appear to stimulate the formation of fibrosis after a cardiac infarction. In this review, the available data on the role of mast cells in cardiovascular disease are summarized, containing both in vitro research and animal studies, followed by a discussion of human data on the association between cardiovascular morbidity and diseases in which mast cells are important: Kounis syndrome, mastocytosis and allergy. Show less
Cardiovascular disease is a major global burden and atherosclerosis is the main underlying pathological process. Despite better management of cholesterol levels, there remains a significant... Show moreCardiovascular disease is a major global burden and atherosclerosis is the main underlying pathological process. Despite better management of cholesterol levels, there remains a significant residual risk of developing atherosclerosis and cardiovascular events. Hence, novel pathways and targets should be identified to optimize atherosclerosis therapy. Despite dyslipidemia, the immune system is also heavily involved in the pathophysiology of atherosclerosis. Protective immune responses in the acute setting of increased cholesterol levels eventually turn into debilitating responses when the immune system is chronically stimulated. Hence, we aimed to identify new therapeutic targets to dampen the immune response in atherosclerosis. More specifically, we focused our efforts on modulating the B lymphocyte response, for which there was a scarcity of data. In this thesis we describe novel ways to modulate the B cell response in atherosclerosis. We have found that there are specific B cell subsets that have different effects on the progress of atherosclerosis. For instance, removal of TIM-1+ B cells resulted in increased atherosclerosis, while removal of BTLA+ follicular B cells reduced atherosclerosis. In conclusion, this thesis provides promising immunological targets for the treatment of atherosclerosis. Show less
Purpose of Review Coronary computed tomography angiography (CCTA) is the optimal non-invasive test to rule out coronary artery disease (CAD). Decisions to perform coronary revascularization have... Show morePurpose of Review Coronary computed tomography angiography (CCTA) is the optimal non-invasive test to rule out coronary artery disease (CAD). Decisions to perform coronary revascularization have traditionally been based upon ischemia testing. This review summarizes the latest observations and trials evaluating the suitability of CCTA to select patients for invasive coronary angiography (ICA) and subsequent revascularization.Recent FindingsRecent data shows that beyond stenosis, whole-heart quantification and characterization of coronary atherosclerotic plaque improves the estimation of myocardial ischemia. This comprehensive evaluation of the coronary artery tree has greater diagnostic accuracy for invasive fractional flow reserve (FFR) than conventional stress tests. Further, clinical trials have demonstrated that the performance of CCTA in patients with a clinical indication for ICA results in more effective patient care and significantly lower costs.SummaryBesides the excellent ability to rule out CAD, recent data shows that quantification and characterization of the coronary artery tree results in high accuracy for ischemia and that CCTA-guided care to select patients for ICA and revascularization is effective. Trials evaluating revascularization based on CCTA findings may be needed. Show less
The presence of mast cells in human atherosclerotic plaques has been associated with adverse cardiovascular events. Mast cell activation, through the classical antigen sensitized-IgE binding to... Show moreThe presence of mast cells in human atherosclerotic plaques has been associated with adverse cardiovascular events. Mast cell activation, through the classical antigen sensitized-IgE binding to their characteristic Fcε-receptor, causes the release of their cytoplasmic granules. These granules are filled with neutral proteases such as tryptase, but also with histamine and pro-inflammatory mediators. Mast cells accumulate in high numbers within human atherosclerotic tissue, particularly in the shoulder region of the plaque. These findings are largely based on immunohistochemistry, which does not allow for the extensive characterization of these mast cells and of the local mast cell activation mechanisms. In this study, we thus aimed to develop a new flow-cytometry based methodology in order to analyze mast cells in human atherosclerosis. We enzymatically digested 22 human plaque samples, collected after femoral and carotid endarterectomy surgery, after which we prepared a single cell suspension for flow cytometry. We were able to identify a specific mast cell population expressing both CD117 and the FcεR, and observed that most of the intraplaque mast cells were activated based on their CD63 protein expression. Furthermore, most of the activated mast cells had IgE fragments bound on their surface, while another fraction showed IgE-independent activation. In conclusion, we are able to distinguish a clear mast cell population in human atherosclerotic plaques, and this study establishes a strong relationship between the presence of IgE and the activation of mast cells in advanced atherosclerosis. Our data pave the way for potential therapeutic intervention through targeting IgE-mediated actions in human atherosclerosis. Show less
Cardiovascular disease is the leading cause of death worldwide. The primary underlying pathology of cardiovascular disease is atherosclerosis. Atherosclerosis is a chronic, multifactorial disease... Show moreCardiovascular disease is the leading cause of death worldwide. The primary underlying pathology of cardiovascular disease is atherosclerosis. Atherosclerosis is a chronic, multifactorial disease in which lipid accumulates in the arterial wall, leading to a local inflammatory reaction and atherosclerotic plaque formation. Atherosclerotic disease develops largely asymptomatic over a lifetime. However, plaque rupture or erosion can cause the formation of a superimposed thrombus, blocking the flow of blood, and cause acute cardiovascular events such as myocardial infarction or ischemic stroke. Defects in cholesterol metabolism and hypercholesterolemia, which are major risk factors for atherosclerosis, have been shown to affect hematopoiesis, immune cell production and platelet counts and reactivity. Therefore, bone marrow cholesterol handling is an interesting target in the battle against cardiovascular disease, and acute cardiovascular events in particular. This thesis describes novel interactions between cholesterol metabolism and the production of immune cells and platelets, and its effects on atherosclerosis and atherothrombosis development. Show less
