Johan Kuiper

Wellcome Trust Sanger Institute, Cambridge, England, United Kingdom

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Publications (194)935.5 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective: Toll like receptor 4 (TLR4) plays a key role in inflammation and previously it was established that TLR4 deficiency attenuates atherosclerosis. RadioProtective 105 (RP105) is a structural homolog of TLR4 and an important regulator of TLR4 signaling, suggesting that RP105 may also be an important effector in atherosclerosis. We thus aimed to determine the role of RP105 in atherosclerotic lesion development using RP105 deficient mice on an atherosclerotic background. Methods and results: Atherosclerosis was induced in Western-type diet fed low density lipoprotein receptor deficient (LDLr(-/-)) and LDLr/RP105 double knockout (LDLr(-/-)/RP105(-/-)) mice by means of perivascular carotid artery collar placement. Lesion size was significantly reduced by 58% in LDLr(-/-)/RP105(-/-) mice, and moreover, plaque macrophage content was markedly reduced by 40%. In a model of acute peritonitis, monocyte influx was almost 3-fold reduced in LDLr(-/-)/RP105(-/-) mice (P = 0.001), while neutrophil influx remained unaltered, suggestive of an altered migratory capacity of monocytes upon deletion of RP105. Interestingly, in vitro stimulation of monocytes with LPS induced a downregulation of CCR2, a chemokine receptor crucially involved in monocyte influx to atherosclerotic lesions, which was more pronounced in LDLr(-/-)/RP105(-/-) monocytes as compared to LDLr(-/-) monocytes. Conclusion: We here show that RP105 deficiency results in reduced early atherosclerotic plaque development with a marked decrease in lesional macrophage content, which may be due to disturbed migration of RP105 deficient monocytes resulting from CCR2 downregulation. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
    Atherosclerosis 11/2014; 238(1):132-139. · 3.71 Impact Factor
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    ABSTRACT: Regulatory T cells (Tregs) play an important role in the regulation of T-cell-mediated immune responses through suppression of T-cell proliferation and secretion of inhibitory cytokines, such as interleukin-10 and transforming growth factor-β. Impaired Treg numbers and function have been associated with numerous diseases, and an imbalance between proinflammatory/proatherogenic cells and Tregs promotes atherosclerotic disease. Restoration of this balance by inducing Tregs has great therapeutic potential to prevent cardiovascular disease. In addition to suppressing differentiation and function of effector T cells, Tregs have been shown to induce anti-inflammatory macrophages, inhibit foam cell formation and to influence cholesterol metabolism. Furthermore, Tregs suppress immune responses of endothelial cells and innate lymphoid cells. In this review, we focus on the recent knowledge on Treg subsets, their activity and function in atherosclerosis, and discuss promising strategies to use Tregs as a therapeutic tool to prevent cardiovascular disease. © 2014 American Heart Association, Inc.
    Arteriosclerosis Thrombosis and Vascular Biology 11/2014; · 6.34 Impact Factor
  • A Wezel, P H A Quax, J Kuiper, I Bot
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    ABSTRACT: Rupture of an atherosclerotic plaque is the major underlying cause of adverse cardiovascular events such as myocardial infarction or stroke. Therapeutic interventions should therefore be directed towards inhibiting growth of atherosclerotic lesions as well as towards prevention of lesion destabilization. Interestingly, the presence of mast cells has been demonstrated in both murine and human plaques, and multiple interventional murine studies have pointed out a direct role for mast cells in early and late stages of atherosclerosis. Moreover, it has recently been described that activated lesional mast cells correlate with major cardiovascular events in patients suffering from cardiovascular disease. This review focuses on the effect of different mast cell derived mediators in atherogenesis and in late stage plaque destabilization. Also, possible ligands for mast cell activation in the context of atherosclerosis are discussed. Finally, we will elaborate on the predictive value of mast cells, together with therapeutic implications, in cardiovascular disease.
    Hamostaseologie 11/2014; 35(1). · 1.59 Impact Factor
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    ABSTRACT: The ubiquitously expressed mannose-6-phosphate receptors (MPRs) are a promising class of receptors for targeted compound delivery into the endolysosomal compartments of a variety of cell types. The development of a synthetic, multivalent, mannose-6-phosphate (M6P) glycopeptide-based MPR ligand is described. The conjugation of this ligand to fluorescent DCG-04, an activity-based probe for cysteine cathepsins, enabled fluorescent readout of its receptor-targeting properties. The resulting M6P-cluster–BODIPY–DCG-04 probe was shown to efficiently label cathepsins in cell lysates as well as in live cells. Furthermore, the introduction of the 6-O-phosphates leads to a completely altered uptake profile in COS and dendritic cells compared to a mannose-containing ligand. Competition with mannose-6-phosphate abolished all uptake of the probe in COS cells, and we conclude that the mannose-6-phosphate cluster targets the MPR and ensures the targeted delivery of cargo bound to the cluster into the endolysosomal pathway.
    Angewandte Chemie 08/2014;
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    ABSTRACT: Complement factor C5a and its receptor C5aR are expressed in vulnerable atherosclerotic plaques; however, a causal relation between C5a and plaque rupture has not been established yet. Accelerated atherosclerosis was induced by placing vein grafts in male apoE−/− mice. After 24 days, when advanced plaques had developed, C5a or PBS was applied locally at the lesion site in a pluronic gel. Three days later mice were killed to examine the acute effect of C5a on late stage atherosclerosis. A significant increase in C5aR in the plaque was detectable in mice treated with C5a. Lesion size and plaque morphology did not differ between treatment groups, but interestingly, local treatment with C5a resulted in a striking increase in the amount of plaque disruptions with concomitant intraplaque haemorrhage. To identify the potential underlying mechanisms, smooth muscle cells and endothelial cells were treated in vitro with C5a. Both cell types revealed a marked increase in apoptosis after stimulation with C5a, which may contribute to lesion instability in vivo. Indeed, apoptosis within the plaque was seen to be significantly increased after C5a treatment. We here demonstrate a causal role for C5a in atherosclerotic plaque disruptions, probably by inducing apoptosis. Therefore, intervention in complement factor C5a signalling may be a promising target in the prevention of acute atherosclerotic complications.
    Journal of Cellular and Molecular Medicine 08/2014; · 4.75 Impact Factor
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    ABSTRACT: Toll-like-receptors (TLRs) provide a critical link between innate and adaptive immune responses. It has been shown that TLR5 ligand Flagellin can enhance the suppressive capacity of regulatory T-cells (Treg), but can also functions as an adjuvant. The immune response in atherosclerosis is characterized by an imbalance of pro- and anti-atherogenic T-cells. We aimed to establish if the TLR5/Flagellin axis is involved in the immune response of atherosclerosis. Methods: We first assessed the effect of Flagellin exposure on macrophage maturation and T-cell polarization. Next, we created TLR5-/-/LDLr-/- chimeras to study the TLR5/Flagellin axis in atherosclerosis. Results: Flagellin exposure to primary macrophages did not result in clear polarization differences, but we did observe a less migratory phenotype (decreased MCP-1, CCR2 expression) in TLR5-/- macrophages. Interestingly, expression of the T-cell polarizing cytokine IL-6 was induced by Flagellin exposure, a phenomenon not observed in TLR5-/- macrophages. Next, we assessed potential T cell polarizing properties of Flagellin. Flagellin can induce expansion of regulatory T-cells, however this induction is completely overruled when Flagellin is used as an adjuvant. Hematopoietic absence of TLR5 significantly attenuates atherosclerotic lesion formation by 25% (1.03±0.06×10(6) μm(2) vs 0.79±0.06 ×10(6) μm(2) in TLR5-/-, p = 0.01). This was accompanied by a decrease in macrophage area (-46%, p = 0.01) and necrotic core size (-32%, p<0.05) while collagen content was similar between groups. Interestingly, plasma levels of IL-6 were significantly lower in TLR5-/- chimeras (40.2±6.3 in WT vs. 15.1±2.7 pg/ml in TLR5-/-, p=0.003). Concomitantly, TLR5-/- chimeras displayed defective T-cell responsiveness, as seen by impaired proliferation and decreased splenic T cell content. In conclusion, hematopoietic TLR5 deficiency inhibits atherosclerotic lesion formation by attenuated macrophage accumulation and defective T cell responsiveness.
    Cardiovascular Research 07/2014; 103(suppl 1):S5. · 5.81 Impact Factor
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    ABSTRACT: Activated mast cells have been identified in atherosclerotic plaques and have previously been established to promote plaque progression and destabilization. As mast cells have the ability to release chemokines that mediate leucocyte fluxes, we propose that activated mast cells play a pivotal role in leucocyte recruitment during the development of atherosclerosis.
    Cardiovascular research. 07/2014; 103(suppl 1):S5.
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    ABSTRACT: Neuropeptide Y is an abundantly expressed neurotransmitter capable of modulating both immune and metabolic responses related to the development of atherosclerosis. NPY receptors are expressed by a number of vascular wall cell types, among which mast cells. However, the direct effects of NPY on atherosclerotic plaque development and progression remain to be investigated. In this study we thus aimed to determine whether NPY is expressed in atherosclerotic plaques and to establish its role in atherosclerotic plaque development.
    Atherosclerosis 05/2014; 235(1):196-203. · 3.71 Impact Factor
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    ABSTRACT: The SDF-1α/CXCR4 dyad was previously shown by us and others to be instrumental in intimal hyperplasia as well as early stage atherosclerosis. We here sought to investigate its impact on clinically relevant stages of atherosclerosis in mouse and man. Immunohistochemical analysis of CXCR4 expression in human atherosclerotic lesions revealed a progressive accumulation of CXCR4(+) cells during plaque progression. To address causal involvement of CXCR4 in advanced stages of atherosclerosis we reconstituted LDLr(-/-) mice with autologous bone marrow infected with lentivirus encoding SDF-1α antagonist or CXCR4 degrakine, which effects proteasomal degradation of CXCR4. Functional CXCR4 blockade led to progressive plaque expansion with disease progression, while also promoting intraplaque haemorrhage. Moreover, CXCR4 knockdown was seen to augment endothelial adhesion of neutrophils. Concordant with this finding, inhibition of CXCR4 function increased adhesive capacity and reduced apoptosis of neutrophils and resulted in hyperactivation of circulating neutrophils. Compatible with a role of the neutrophil CXCR4 in end-stage atherosclerosis, CXCR4 expression by circulating neutrophils was lowered in patients with acute cardiovascular syndromes. In conclusion, CXCR4 contributes to later stages of plaque progression by perturbing neutrophil function.
    Journal of Molecular and Cellular Cardiology 05/2014; · 5.15 Impact Factor
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    ABSTRACT: Recently, we have shown that intraplaque mast cell numbers are associated with atherosclerotic plaque vulnerability and with future cardiovascular events, which renders inhibition of mast cell activation of interest for future therapeutic interventions. However, the endogenous triggers that activate mast cells during the progression and destabilization of atherosclerotic lesions remain unidentified. Mast cells can be activated by immunoglobulins and in the present study, we aimed to establish whether specific immunoglobulins in plasma of patients scheduled for carotid endarterectomy were related to (activated) intraplaque mast cell numbers and plasma tryptase levels. In addition, the levels were related to other vulnerable plaque characteristics and baseline clinical data. OxLDL-IgG, total IgG and total IgE levels were measured in 135 patients who underwent carotid endarterectomy. No associations were observed between the tested plasma immunoglobulin levels and total mast cell numbers in atherosclerotic plaques. Furthermore, no associations were found between IgG levels and the following plaque characteristics: lipid core size, degree of calcification, number of macrophages or smooth muscle cells, amount of collagen and number of microvessels. Interestingly, statin use was negatively associated with plasma IgE and oxLDL-IgG levels. In patients suffering from carotid artery disease, total IgE, total IgG and oxLDL-IgG levels do not associate with plaque mast cell numbers or other vulnerable plaque histopathological characteristics. This study thus does not provide evidence that the immunoglobulins tested in our cohort play a role in intraplaque mast cell activation or grade of atherosclerosis.
    PLoS ONE 01/2014; 9(2):e88984. · 3.53 Impact Factor
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    ABSTRACT: Aims The SDF-1α/CXCR4 dyad was previously shown by us and others to be instrumental in intimal hyperplasia as well as early stage atherosclerosis. We here sought to investigate its impact on clinically relevant stages of atherosclerosis in mouse and man. Methods and results Immunohistochemical analysis of CXCR4 expression in human atherosclerotic lesions revealed a progressive accumulation of CXCR4+ cells during plaque progression. To address causal involvement of CXCR4 in advanced stages of atherosclerosis we reconstituted LDLr−/− mice with autologous bone marrow infected with lentivirus encoding SDF-1α antagonist or CXCR4 degrakine, which effects proteasomal degradation of CXCR4. Functional CXCR4 blockade led to progressive plaque expansion with disease progression, while also promoting intraplaque haemorrhage. Moreover, CXCR4 knockdown was seen to augment endothelial adhesion of neutrophils. Concordant with this finding, inhibition of CXCR4 function increased adhesive capacity and reduced apoptosis of neutrophils and resulted in hyperactivation of circulating neutrophils. Compatible with a role of the neutrophil CXCR4 in end-stage atherosclerosis, CXCR4 expression by circulating neutrophils was lowered in patients with acute cardiovascular syndromes. Conclusion In conclusion, CXCR4 contributes to later stages of plaque progression by perturbing neutrophil function.
    Journal of Molecular and Cellular Cardiology 01/2014; 74:44–52. · 5.15 Impact Factor
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    ABSTRACT: Genetic factors explain a proportion of the inter-individual variation in the risk for atherosclerotic events, but the genetic basis of atherosclerosis and atherothrombosis in families with Mendelian forms of premature atherosclerosis is incompletely understood. We set out to unravel the molecular pathology in a large kindred with an autosomal dominant inherited form of premature atherosclerosis.
    PLoS ONE 01/2014; 9(5):e98289. · 3.53 Impact Factor
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    ABSTRACT: To characterize the phenotype of Akt2/low-density-lipoprotein receptor double knockout (Akt2/LDLr dKO) mice with respect to insulin resistance and features of atherosclerotic plaque progression. Metabolic profile and atherosclerotic plaque progression were compared between LDLr KO mice and Akt2/LDLr dKO mice. Total cholesterol, glucose and insulin levels were significantly higher and oral glucose tolerance test was more impaired in Akt2/LDLr dKO mice than in LDLr KO mice. Although atherosclerotic plaques at both the carotid artery and the aortic root of Akt2/LDLr dKO mice were significantly smaller (p<0.05) compared with LDLr KO controls, plaque composition in these mice was more complex, showing 34-50% reduced collagen content (p<0.01), 1.4-fold larger necrotic cores (p<0.05) and 6-fold more TUNEL positive cells (p<0.01). In situ zymography revealed a more than two-fold higher gelatinolytic activity in Akt2/LDLr dKO mice (p<0.05). In vitro analyses showed that deletion of Akt2 caused decreased migration, proliferation and collagen content of vascular smooth muscle cells (VSMCs) and disturbed the balance of metalloproteinases (MMPs) and tissue inhibitor of metalloproteinase (TIMP) mRNA expression in macrophages and VSMCs. Akt2/LDLr dKO mice develop insulin resistance and complex atherosclerotic lesions. These phenotypic characteristics make Akt2/LDLr dKO mice an interesting mouse model to study the effects of insulin resistance on the development and progression of atherosclerosis.
    Cardiovascular Research 11/2013; · 5.81 Impact Factor
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    ABSTRACT: In atherosclerosis, Toll-like receptors (TLRs) are traditionally linked to effects on tissue macrophages or foam cells. RP105, a structural TLR4 homolog, is an important regulator of TLR signaling. The effects of RP105 on TLR signaling vary for different leukocyte subsets known to be involved in atherosclerosis, making it unique in its role of either suppressing (in myeloid cells) or enhancing (in B cells) TLR-regulated inflammation in different cell types. We aimed to identify a role of TLR accessory molecule RP105 on circulating cells in atherosclerotic plaque formation. Irradiated LDLr(-/-) mice received RP105(-/-) or wild-type bone marrow. RP105(-/-) chimeras displayed a 57% reduced plaque burden. Interestingly, total and activated B-cell numbers were significantly reduced in RP105(-/-) chimeras. Activation of B1 B cells was unaltered, suggesting that RP105 deficiency only affected inflammatory B2 B cells. IgM levels were unaltered, but anti-oxidized low-density lipoprotein and anti-malondialdehyde-modified low-density lipoprotein IgG2c antibody levels were significantly lower in RP105(-/-) chimeras, confirming effects on B2 B cells rather than B1 B cells. Moreover, B-cell activating factor expression was reduced in spleens of RP105(-/-) chimeras. RP105 deficiency on circulating cells results in an intriguing unexpected TLR-associated mechanisms that decrease atherosclerotic lesion formation with alterations on proinflammatory B2 B cells.
    Arteriosclerosis Thrombosis and Vascular Biology 10/2013; · 6.34 Impact Factor
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    ABSTRACT: Patients suffering from cardiovascular disease have well-established atherosclerotic lesions, rendering lesion regression of therapeutic interest. The OX40 (TNFRSF4)-OX40 ligand (OX40L; TNFSF4) pathway is important for the proliferation and survival of T cells, stimulates B cells, and is associated with cardiovascular disease. We hypothesized that interference with the OX40-OX40L pathway, in combination with decreases in cholesterol, may induce regression of atherosclerosis. LDLr(-/-) mice were fed a Western-type diet for 10 wk, after which they received chow diet and were treated with anti-OX40L or PBS for 10 wk. A significant regression of lesions was observed in the aorta and aortic arch of anti-OX40L-treated mice compared with control mice. Interference of the OX40-OX40L pathway reduced Th2 responses, as shown by decreases in GATA-3 and IL-4 levels. Also, IgE levels were decreased, as demonstrated by reduced mast cell presence and activation. Notably, IL-5 production by T and B1 cells was increased, thus enhancing atheroprotective oxidized low-density lipoprotein-specific IgM production. The increase in IL-5 production and IgM was mediated by IL-33 production by APCs upon OX40L blockade. We conclude that interruption of the OX40-OX40L signaling pathway, combined with decreases in dietary cholesterol, induces the regression of atherosclerosis through induction of IL-5-producing T cells and oxidized low-density lipoprotein-specific IgM and reductions in Th2 and mast cells.
    The Journal of Immunology 09/2013; · 5.52 Impact Factor
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    ABSTRACT: Atherosclerosis is a chronic autoimmune-like disease in which lipids and fibrous elements accumulate in the arterial blood vessels. T cells are present within atherosclerotic plaques, and their activation is partially dependent on costimulatory signals, which can either provide positive or negative signals that promote T-cell activation or limit T-cell responses, respectively. T-cell immunoglobulin and mucin domain 3 (Tim-3) is a coinhibitory type 1 transmembrane protein that affects the function of several immune cells involved in atherosclerosis, such as monocytes, macrophages, effector T cells, and regulatory T cells. In the present study, we determined the role of Tim-3 in the development of atherosclerosis. Western-type diet-fed LDLr(-/-) mice were treated with an anti-Tim-3 antibody for 3 and 8 weeks. Anti-Tim-3 administration increased fatty streak formation with 66% and increased atherosclerotic plaque formation after 8 weeks with 35% in the aortic root and with 50% in the aortic arch. Furthermore, blockade of Tim-3 signaling increased percentages of circulating monocytes with 33% and lesional macrophages with 20%. In addition, anti-Tim-3 administration increased CD4(+) T cells with 17%, enhanced their activation status, and reduced percentages of regulatory T cells with 18% and regulatory B cells with 37%. It is known that Tim-3 acts as a negative regulator of both innate and adaptive immune responses, and in the present study, we show that anti-Tim-3 treatment augments lesion development, accompanied by an increase in the number of monocytes/macrophages and CD4(+) T cells and by decreased regulatory T cells and regulatory B cells.
    Arteriosclerosis Thrombosis and Vascular Biology 08/2013; · 6.34 Impact Factor
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    ABSTRACT: Biomarkers for primary or secondary risk prediction of cardiovascular disease (CVD) are urgently needed to improve individual treatment and clinical trial design. The vast majority of biomarker discovery studies has concentrated on plasma/serum as an easily accessible source. Although numerous markers have been identified, their added predictive value on top of traditional risk factors has been limited, as the biological specimen does not specifically reflect expression profiles related with CVD progression and because the signal is often diluted by marker release from other organs. In contrast to serum markers, circulating cells serve as indicators of the actual disease state due to their active role in the pathogenesis of CVD and are responsible for the majority of secreted biomarkers. Therefore, the CIRCULATING CELLS study was initiated, focusing on the cellular effectors of atherosclerosis in the circulation. In total, 714 patients with coronary artery disease (CAD) symptoms were included. Blood cell fractions (monocytes, T-lymphocytes, platelets, granulocytes, PBMC) of all individual patients were isolated and stored for analysis. Concomitantly, extensive flow cytometric characterization of these populations was performed. From each patient, a detailed clinical profile together with extensive questionnaires about medical history and life style was obtained. Various high-throughput -omics approaches (protein, mRNA, miRNA) are currently being undertaken. Data will be integrated with advanced bioinformatics for discovery and validation of secondary risk markers for adverse events. Overall, the CIRCULATING CELLS study grants the interesting possibility that it will both identify novel biomarkers and provide useful insights into the pathophysiology of CAD in patients.
    Clinical Research in Cardiology 08/2013; · 3.67 Impact Factor
  • Johan Kuiper, Paul H A Quax, Ilze Bot
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    ABSTRACT: Acute cardiovascular syndromes such as myocardial infarction and stroke are a major cause of death in the Western society and are generally caused by rupture of an atherosclerotic plaque. Treatment of atherosclerosis, the main underlying cause of acute cardiovascular syndromes, is still inadequate for most of the patients. Therefore, there is a need for new therapeutic strategies in addition to the existing lipid-lowering drugs such as statins. Lipid accumulation, inflammation and matrix degradation are generally considered key processes in the pathogenesis of atherosclerosis and that of plaque rupture. Furthermore, apoptosis or programmed cell death of plaque cells, depending on the disease stage, is thought to be of importance in the development and progression of atherosclerosis and the incidence of acute cardiovascular syndromes. Serine protease inhibitors or so-called serpins have been demonstrated to be involved in both the induction and inhibition of apoptosis and may thus be of interest as therapeutics in cardiovascular diseases such as atherosclerosis. In this review, we will discuss the current knowledge on the role of serpins in cardiovascular diseases with particular emphasis on apoptotic cell death and the potential therapeutic applications.
    Cardiovascular & hematological disorders drug targets. 08/2013; 13(2):111-22.
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    ABSTRACT: AIMS: Human autopsy, animal, and cell culture studies together have merged in a concept suggesting participation of mast cells (MCs) in the generation of atherosclerotic plaques. More specifically, these studies have suggested MC-induced intraplaque neovascularization as one mechanism by which MCs may render the plaques vulnerable. The present study was designed to assess the association between MC numbers and neovascularization in human atherosclerotic plaques, and to relate the abundance of plaque MCs to the occurrence of adverse cardiovascular events during the follow-up. METHODS AND RESULTS: Atherosclerotic plaques of 270 patients suffering from carotid artery stenosis were stained for the presence of MCs (MC tryptase). Furthermore, during a follow-up of 3 years, cardiovascular-related endpoints were assessed in 253 patients. On average a high number of MCs were observed per plaque cross-section [median 108 (55-233) cells per section]. Plaques with high MC numbers revealed an unstable lipid-rich inflammatory phenotype and were associated with symptomatic patients. In addition, MC numbers were positively associated with microvessel density (r = 0.416, P < 0.001). Patients with high intraplaque MC numbers showed significantly more cardiovascular events during the follow-up (58/142 vs. 31/111 events, P = 0.029). In a multivariate analysis with correction for the main risk factors of cardiovascular diseases, MCs remained independently associated with adverse cardiovascular events (P = 0.025). CONCLUSION: Mast cells are highly prevalent in human carotid atherosclerotic lesions and associated with plaque microvessel density. Furthermore, intraplaque MC numbers associate with future cardiovascular events.
    European Heart Journal 06/2013; · 14.72 Impact Factor
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    ABSTRACT: Abstract Objective: Lysophosphatidic acid (LPA), a bioactive lysophospholipid, accumulates in the atherosclerotic plaque. It has the capacity to activate mast cells, which potentially exacerbates plaque progression. In this study, we thus aimed to investigate whether LPA contributes to plaque destabilization by modulating mast cell function. Methods and Results: We here show by an imaging mass spectrometry approach that several LPA species are present in atherosclerotic plaques. Subsequently, we demonstrate that LPA is a potent mast cell activator, which unlike other triggers favor release of tryptase. Local perivascular administration of LPA to an atherosclerotic carotid artery segment increases the activation status of perivascular mast cells and promotes intraplaque hemorrhage, macrophage recruitment, without impacting plaque cell apoptosis. The mast cell stabilizer cromolyn could prevent intraplaque hemorrhage elicited by LPA-mediated mast cell activation. Finally, the involvement of mast cells in these events was further emphasized by the lack of effect of perivascular LPA administration in mast cell deficient animals. Conclusions: We demonstrate that increased accumulation of LPA in plaques induces perivascular mast cell activation and in this way contribute to plaque destabilization in vivo. This study points to local LPA availability as an important factor in atherosclerotic plaque stability.
    The Journal of Lipid Research 02/2013; · 4.39 Impact Factor

Publication Stats

4k Citations
935.50 Total Impact Points

Institutions

  • 2014
    • Wellcome Trust Sanger Institute
      Cambridge, England, United Kingdom
  • 1988–2014
    • Leiden University
      • Leiden Amsterdam Center for Drug Research
      Leyden, South Holland, Netherlands
    • Erasmus Universiteit Rotterdam
      Rotterdam, South Holland, Netherlands
  • 2012–2013
    • Leiden University Medical Centre
      • Department of Surgery
      Leyden, South Holland, Netherlands
    • Technische Universiteit Eindhoven
      Eindhoven, North Brabant, Netherlands
  • 2002
    • TNO
      Delft, South Holland, Netherlands