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Kuhnast S.,TNO | Kuhnast S.,Einthoven Laboratory for Experimental Vascular Medicine | Fiocco M.,LUMC | Fiocco M.,Leiden University | And 4 more authors.
European Journal of Pharmacology

Non-HDL-cholesterol is well recognised as a primary causal risk factor in cardiovascular disease. However, despite consistent epidemiological evidence for an inverse association between HDL-C and coronary heart disease, clinical trials aimed at raising HDL-C (AIM-HIGH, HPS2-THRIVE, dal-OUTCOMES) failed to meet their primary goals. This systematic review and meta-analysis investigated the effects of established and novel treatment strategies, specifically targeting HDL, on inhibition of atherosclerosis in cholesteryl ester transfer protein-expressing animals, and the prevention of clinical events in randomised controlled trials. Linear regression analyses using data from preclinical studies revealed associations for TC and non-HDL-C and lesion area (R2=0.258, P=0.045; R2=0.760, P<0.001), but not for HDL-C (R2=0.030, P=0.556). In clinical trials, non-fatal myocardial infarction risk was significantly less in the treatment group with pooled odd ratios of 0.87 [0.81; 0.94] for all trials and 0.85 [0.78; 0.93] after excluding some trials due to off-target adverse events, whereas all-cause mortality was not affected (OR 1.05 [0.99-1.10]). Meta-regression analyses revealed a trend towards an association between between-group differences in absolute change from baseline in LDL-C and non-fatal myocardial infarction (P=0.066), whereas no correlation was found for HDL-C (P=0.955). We conclude that the protective role of lowering LDL-C and non-HDL-C is well-established. The contribution of raising HDL-C on inhibition of atherosclerosis and the prevention of cardiovascular disease remains undefined and may be dependent on the mode of action of HDL-C-modification. Nonetheless, treatment strategies aimed at improving HDL function and raising apolipoprotein A-I may be worth exploring. © 2015 Elsevier B.V. All rights reserved. Source

De Vries M.R.,Einthoven Laboratory for Experimental Vascular Medicine | De Vries M.R.,Leiden University | Wezel A.,Leiden University | Schepers A.,Leiden University | And 8 more authors.
Cardiovascular Research

AimsFailure of vein graft conduits due to vein graft thickening, accelerated atherosclerosis, and subsequent plaque rupture is applicable to 50% of all vein grafts within 10 years. New potential therapeutic targets to treat vein graft disease may be found in components of the innate immune system, such as mast cells and complement factors, which are known to be involved in atherosclerosis and plaque destabilization. Interestingly, mast cells can be activated by complement factor C5a and, therefore, a direct role for C5a-mediated mast cell activation in vein graft disease is anticipated. We hypothesize that C5a-mediated mast cell activation is involved in the development and destabilization of vein graft lesions.Methods and resultsMast cells accumulated in time in murine vein graft lesions, and C5a and C5a-receptor (CD88) expression was up-regulated during vein graft disease in apolipoprotein E-deficient mice. Mast cell activation with dinitrophenyl resulted in a profound increase in vein graft thickening and in the number of plaque disruptions. C5a application enhanced vein graft lesion formation, while treatment with a C5a-receptor antagonist resulted in decreased vein graft disease. C5a most likely exerts its function via mast cell activation since the mast cell inhibitor cromolyn totally blocked C5a-enhanced vein graft disease. ConclusionThese data provide evidence that complement factor C5a-induced mast cell activation is highly involved in vein graft disease, which identifies new targets to prevent vein graft disease. © 2013 The Author. Source

Van Klinken J.B.,Einthoven Laboratory for Experimental Vascular Medicine | Willems Van Dijk K.,Einthoven Laboratory for Experimental Vascular Medicine

Elementary flux mode (EFM) analysis is a powerful technique for determining the metabolic capacities and robustness of stoichiometric networks. Recently, several improvements have been made to the algorithm for enumerating the EFMs, making the study of large models possible. However, currently these tools require high performance workstations to perform large-scale EFM computations, thus limiting their applicability. We developed a more time and memory efficient implementation of the algorithm for EFM enumeration in MATLAB, called FluxModeCalculator, which enables large-scale EFM computation on ordinary desktop computers. © 2015 The Author. All rights reserved. Source

Arslan F.,University Utrecht | Arslan F.,Netherlands Heart Institute | Smeets M.B.,University Utrecht | Riem Vis P.W.,University Utrecht | And 12 more authors.
Circulation Research

Rationale: The extracellular matrix may induce detrimental inflammatory responses on degradation, causing adverse cardiac remodeling and heart failure. The extracellular matrix protein fibronectin-EDA-/- (EIIIA; EDA) is upregulated after tissue injury and may act as a "danger signal" for leukocytes to cause adverse cardiac remodeling after infarction. Objective: In the present study, we evaluated the role of EDA-/- in regulation of postinfarct inflammation and repair after myocardial infarction. Methods and Results: Wild-type and EDA-/- mice underwent permanent ligation of the left anterior coronary artery. Despite equal infarct size between groups (38.2±4.6% versus 38.2±2.9% of left ventricle; P=0.985), EDA -/- mice exhibited less left ventricular dilatation and enhanced systolic performance compared with wild-type mice as assessed by serial cardiac MRI measurements. In addition, EDA-/- mice exhibited reduced fibrosis of the remote area without affecting collagen production, cross-linking, and deposition in the infarct area. Subsequently, ventricular contractility and relaxation was preserved in EDA-/-. At tissue level, EDA -/- mice showed reduced inflammation, metalloproteINase 2 and 9 activity, and myofibroblast transdifferentiation. Bone marrow transplantation experiments revealed that myocardium-induced EDA-/- and not EDA-/- from circulating cells regulates postinfarct remodeling. FINally, the absence of EDA-/- reduced monocyte recruitment as well as monocytic Toll-like receptor 2 and CD49d expression after infarction. Conclusions: Our study demonstrated that parenchymal fn-EDA-/- plays a critical role in adverse cardiac remodeling after infarction. Absence of fn-EDA-/- enhances survival and cardiac performance by modulating matrix turnover and inflammation via leukocytes and fibroblasts after infarction. © 2011 American Heart Association, Inc. Source

Lips M.A.,Leiden University | Van Klinken J.B.,Leiden University | Van Harmelen V.,Leiden University | Dharuri H.K.,Leiden University | And 17 more authors.
Diabetes Care

OBJECTIVE: Obesity and type 2 diabetes mellitus (T2DM) have been associated with increased levels of circulating branched-chain amino acids (BCAAs) that may be involved in the pathogenesis of insulin resistance. However, weight loss has not been consistently associated with the reduction of BCAA levels. RESEARCH DESIGN AND METHODS: We included 30 obese normal glucose-tolerant (NGT) subjects, 32 obese subjects with T2DM, and 12 lean female subjects. Obese subjects underwent either a restrictive procedure (gastric banding [GB], a very low-calorie diet [VLCD]), or a restrictive/bypass procedure (Roux-en-Y gastric bypass [RYGB] surgery). Fasting blood samples were taken for the determination of amine group containing metabolites 4 weeks before, as well as 3 weeks and 3 months after the intervention. RESULTS: BCAA levelswere higher in T2DM subjects, but not in NGT subjects, compared with lean subjects. Principal component (PC) analysis revealed a concise PC consisting of all BCAAs, which showed a correlation with measures of insulin sensitivity and glucose tolerance. Only after the RYGB procedure, and at both 3 weeks and 3 months, were circulating BCAA levels reduced. CONCLUSIONS: Our data confirm an association between deregulation of BCAA metabolism in plasma and insulin resistance and glucose in tolerance. Three weeks after undergoing RYGB surgery, a significant decrease in BCAAs in both NGT as well as T2DM subjects was observed. After 3 months, despite inducing significant weight loss, neither GB nor VLCD induced a reduction in BCAA levels. Our results indicate that the bypass procedure of RYGB surgery, independent of weight loss or the presence of T2DM, reduces BCAA levels in obese subjects. © 2014 by the American Diabetes Association. Source

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