Dietary enrichment of apolipoprotein E-deficient mice with extra virgin olive oil in combination with seal oil inhibits atherogenesis

Background: In this study we investigated the antiatherogenic effect of dietary enrichment of a combination of extra virgin olive oil (EVO) and seal oil on apolipoprotein E-deficient (apoE(-/-)). Methods: Six-week-old female and male apoE(-/-) mice were for 12 weeks fed a lipid rich diet containing 19.5% fat and 1.25% cholesterol without any supplement, with 1% (wt/wt) mixture of extra virgin olive and seal oil (EVO/n-3), or 1% corn oil, respectively. Results: Supplementation with the combination of EVO/n-3 significantly reduced atherosclerotic lesion formation in the aortic arch, thoracoabdominal, and total aorta of female apoE(-/-) mice. The effect was less pronounced in male mice and significant reduction was only observed in the thoracoabdominal region of the aorta. There were no differences or changes in dietary intake or body weight gain. However, compared to the other groups, plasma levels of triglycerides were reduced in both female and male mice fed the EVO/n-3 mixture. Male mice on both treatments showed reduced plasma cholesterol compared to the control mice after 12 weeks on diet. Conclusion: Dietary supplementation of a marine/olive oil combination inhibits atherosclerotic lesion formation in the female apoE(-/-) mice by antithrombotic, antihypertriglyceridemic, and antioxidant effects

Rational optimization of a short human P-selectin-binding peptide leads to nanomolar affinity antagonists

2400506

PEAR1 is not a major susceptibility gene for cardiovascular disease in a Flemish population

Background: Platelet Endothelial Aggregation Receptor 1 (PEAR1), a membrane protein highly expressed in platelets and endothelial cells, plays a role in platelet contact-induced activation, sustained platelet aggregation and endothelial function. Previous reports implicate PEAR1 rs12041331 as a variant influencing risk in patients with coronary heart disease. We investigated whether genetic variation in PEAR1 predicts cardiovascular outcome in a white population. Methods: In 1938 participants enrolled in the Flemish Study on Environment, Genes and Health Outcomes (51.3% women; mean age 43.6years), we genotyped 9 tagging SNPs in PEAR1, measured baseline cardiovascular risk factors, and recorded Cardiovascular disease incidence. For SNPs, we contrasted cardiovascular disease incidence of minor-allele heterozygotes and homozygotes (variant) vs. major-allele homozygotes (reference) and for haplotypes carriers vs. non-carriers. In adjusted analyses, we accounted for family clusters and baseline covariables, including sex, age, body mass index, mean arterial pressure, the total-to-HDL cholesterol ratio, smoking and drinking, antihypertensive drug treatment, and history of cardiovascular disease and diabetes mellitus. Results: Over a median follow-up of 15.3years, 238 died and 181 experienced a major cardiovascular endpoint. The multivariable-adjusted hazard ratios of eight PEAR1 SNPs, including rs12566888, ranged from 0.87 to 1.07 (P 650.35) and from 0.78 to 1.30 (P 650.15), respectively. The hazard ratios of three haplotypes with frequency 6510% ranged from 0.93 to 1.11 (P 650.49) for mortality and from 0.84 to 1.03 (P 650.29) for a cardiovascular complications. These results were not influenced by intake of antiplatelet drugs, nonsteroidal anti-inflammatory drugs, or both (P-values for interaction 650.056). Conclusions: In a White population, we could not replicate previous reports from experimental studies or obtained in patients suggesting that PEAR1 might be a susceptibility gene for cardiovascular complications

Controlled NO-Release from 3D-Printed Small-Diameter Vascular Grafts Prevents Platelet Activation and Bacterial Infectivity

Thrombogenicity and bacterial infectiveness are the most common complications for foreign blood contacting surfaces associated with functional failure of small-diameter vascular grafts (SDVGs). In this work, novel bactericidal and nonthrombogenic SDVGs were manufactured via 3D-printing technology, thus producing a controlled nitric oxide (NO) release coating. S-Nitroso-N-acetyl-D-penicillamine (SNAP) was synthesized as an NO-donor, and three biomedical grade composite matrixes of poly(ethylene glycol) (PEG)-SNAP, polycaprolactone (PCL)-SNAP, and PEG-PCL-SNAP were validated for water uptake and NO-release kinetics. To optimize and extend the NO releasing profile, a PCL top-coat (tc) was deposited over the NO-releasing layer. The PEG-PCL-SNAP-tc was selected for biological tests as its NO-release profile was prolonged and well-controlled. Coating the 3D-printed SDVG with PEG-PCL-SNAP-tc resulted in quantitative antibacterial features against both Gram-positive and Gram-negative bacteria and in NO-mediated inhibition of platelet activation and aggregation. Antibacterial and antithrombogenic properties in plasma are expected to be as effective as in PBS, since NO release in plasma was not significantly different from that in PBS. Overall, application of the inexpensive, rapid, and reproducible 3D-printing technology as a custom-based production method, in combination with a well-controlled NO release system, is promising for the production of innovative bactericidal and hemocompatible SDVGs. © 2019 American Chemical Society

Pulmonary exposure to carbon nanotubes promotes murine arterial thrombogenesis via platelet P-selectin

Carbon nanotubes, having a diameter as small as a few nanometers, yet with robust mechanical properties, can be functionalized with chemical and biological agents and be used for the delivery of target DNA molecules or peptides into specific tissues. However, their potential adverse health effects remain unknown. Here, we studied the acute (24 h) effects of intratracheally administered (200 and 400 µg) multi-wall ground carbon nanotubes (CNT) on lung inflammation assessed by bronchoalveolar lavage (BAL), and peripheral arterial thrombogenicity in mice. The latter was evaluated from the extent of photochemically induced thrombosis in the carotid artery, measured via transillumination. I.t. instillation of CNT induced a dose-dependent influx of neutrophils in BAL, paralleled by enhanced experimental arterial thrombus formation. By flow cytometry, circulating platelet-leukocyte conjugates were found to be elevated 6 h after i.t. instillation of CNT. The pretreatment of mice with a blocking anti-P-selectin antibody prevented the formation of platelet conjugates in the circulation but did not affect neutrophil influx in the lung. Although P-selectin neutralization had no effect on the vascular injury triggered thrombus formation in saline-treated mice, it abrogated the CNT induced thrombotic amplification. We conclude that the CNT induced lung inflammation is responsible for systemic platelet activation and subsequent platelet P-selectin mediated thrombogenicity. Our findings uncover that newly engineered CNT affect not only the respiratory but also cardiovascular integrity, necessitating an evaluation of their potential risk for human health

Explanations for coagulation activation after air travel

Background: It is unknown whether venous thrombosis after long haul air travel is exclusively attributable to immobilization. Objectives: We determined whether the following mechanisms were involved: hypoxia, stress, inflammation or viral infection. Patients/Methods: In a case crossover setting in 71 healthy volunteers who were exposed to an 8-h flight, 8-h movie marathon and 8 h of regular activities, we compared markers for several hypothetical pathways: plasminogen activator inhibitor-1 (PAI-1), stress, plasma factor (F)VIII coagulant activity (FVIIIc), soluble P-selectine (sP-selectine), interleukin-8 (IL-8) and neutrophil elastase. We reported earlier an activated clotting system, as evidenced by thrombin generation, in 17% of volunteers after the flight. Results: PAI-1 increased by 4.2 ng mL-1 (CI95:-49.5 to 6.5) in volunteers with an activated clotting system whereas it decreased in those without (-20.0 ng mL-1, CI95:-33.2 to -14.0). FVIIIc levels rose more in individuals with clotting activation (18.0%, CI95:-1.0 to 33.0) than in those without (2.0%, CI95:-2.0 to 5.0). The increases in FVIIIc were not associated with stress, which appeared unrelated to clotting activation. sP-selectin increased in those with clotting activation (3.5 mu g L-1, CI95: -3.0 to 10.0), but decreased in those without (-0.5 mu g L-1, CI95: -2.0 to 2.0). Changes in levels of neutrophil elastase or IL-8 were not different between the subjects with and without clotting activation. Conclusions: Our results do not support the hypotheses that stress, infection or air pollution are involved in the development of a prothrombotic state in air travellers. After long haul air travel, this state is more pronounced in patients with risk factors and may be caused by hypoxia, triggering systemic inflammation and platelet activation, leading to coagulation induction and degranulation of platelets.Thrombosis and Hemostasi

Antiplatelet therapy abrogates platelet-assisted Staphylococcus aureus infectivity of biological heart valve conduits.

Although recent advances in pulmonary valve replacement have enabled excellent hemodynamics, infective endocarditis remains a serious complication, particularly for implanted bovine jugular vein (BJV) conduits. We investigated contributions by platelets and plasma fibrinogen to endocarditis initiation on various grafts used for valve replacement. Thus, adherence of Staphylococcus aureus and platelets to 5 graft tissues was studied quantitatively in perfusion chambers, assisted by microscopic analysis. We also evaluated standard antiplatelet therapy to prevent onset of S aureus endocarditis. Of all tissues, bovine pericardium (BP) showed the greatest fibrinogen binding. Perfusion of all plasma-precoated tissues identified BP and BJV <sub>wall</sub> with the greatest affinity for S aureus. Perfusions of anticoagulated human blood over all tissues also triggered more platelet adhesion to BP and BJV <sub>wall</sub> as single platelets. Several controls confirmed that both S aureus and platelets were recruited on immobilized fibrinogen. In addition, perfusions (and controls) over plasma-coated tissues with whole blood, spiked with S aureus, revealed that bacteria exclusively bound to adhered platelets. Both the platelet adhesion and platelet-mediated S aureus recruitment required platelet α <sub>IIb</sub> β <sub>3</sub> and coated or soluble fibrinogen, respectively, interactions abrogated by the α <sub>IIb</sub> β <sub>3</sub> -antagonist eptifibatide. Also, standard antiplatelet therapy (aspirin/ticagrelor) reduced the adherence of S aureus in blood to BJV 3-fold. Binding of plasma fibrinogen to especially BJV grafts enables adhesion of single platelets via α <sub>IIb</sub> β <sub>3</sub> . S aureus then attaches from blood to (activated) bound platelet α <sub>IIb</sub> β <sub>3</sub> via plasma fibrinogen. Dual antiplatelet therapy appears a realistic approach to prevent endocarditis and its associated mortality

Assessment of the Dual Role of Clumping Factor A in S. Aureus Adhesion to Endothelium in Absence and Presence of Plasma.

Adhesion of Staphylococcus aureus to endothelial cells (ECs) is paramount in infective endocarditis. Bacterial proteins such as clumping factor A (ClfA) and fibronectin binding protein A (FnbpA) mediate adhesion to EC surface molecules and (sub)endothelial matrix proteins including fibrinogen (Fg), fibrin, fibronectin (Fn) and von Willebrand factor (vWF). We studied the influence of shear flow and plasma on the binding of ClfA and FnbpA (including its sub-domains A, A <sup>16+</sup> , ABC, CD) to coverslip-coated vWF, Fg/fibrin, Fn or confluent ECs, making use of Lactococcus lactis, expressing these adhesins heterologously. Global adherence profiles were similar in static and flow conditions. In the absence of plasma, L. lactis-clfA binding to Fg increased with shear forces, whereas binding to fibrin did not. The degree of adhesion of L. lactis-fnbpA to EC-bound Fn and of L. lactis-clfA to EC-bound Fg, furthermore, was similar to that of L. lactis-clfA to coated vWF domain A1, in the presence of vWF-binding protein (vWbp). Yet, in plasma, L. lactis-clfA adherence to activated EC-vWF/vWbp dropped over 10 minutes by 80% due to vWF-hydrolysis by a disintegrin and metalloproteinase with thrombospondin type 1 motif, member 13 and that of L. lactis-fnbpA likewise by > 70% compared to the adhesion in absence of plasma. In contrast, plasma Fg supported high L. lactis-clfA binding to resting and activated ECs. Or, in plasma S. aureus adhesion to active endothelium occurs mainly via two complementary pathways: a rapid but short-lived vWF/vWbp pathway and a stable integrin-coupled Fg-pathway. Hence, the pharmacological inhibition of ClfA-Fg interactions may constitute a valuable additive treatment in infective endocarditis