Plasma P-selectin Research Articles

Association of Systemic Thromboxane Generation With Risk of Developing HeartFailure.

Systemic thromboxane A2 generation, which is readily assessed by quantifying thromboxane B2 metabolites (TXB2-M) in the urine, is associated with impaired cardiac performance and mortality in aspirin (ASA) users with heart failure (HF). This study sought to determine the association of urinary TXB2-M with the risk of developing HF in individuals without prior history of HF and with normal left ventricular function irrespective of ASA use. Urine TXB2-M were measured by immunoassay and adjusted to urine concentration and renal function (TXB2-MGFR) in 2,611 Framingham Heart Study participants (54.9% women, mean age 65 ± 9 years, 43.8% ASA users) without prior history of HF and with left ventricular ejection fraction (LVEF)≥55%. The association of TXB2-MGFR with HF risk over a median observation period of 14.8 years (Q1-Q3: 12.6-15.7 years) was modeled using Cox regression. HF occurred in 189 participants (7.2%), with 104 of the first events (55.0%) classified as HF with preserved LVEF, 56 (29.6%) as HF with reduced LVEF, and 29 (15.3%) were unclassifiable. TXB2-MGFR levels, above compared to below, of 16.6 and 62.1 filtered prostanoid units for ASA users and nonusers, respectively, were associated with increased risk of developing HF (HR: 1.81; 95%CI: 1.38-2.64; P< 0.0001, adjusted for age, sex, ASA use, and HF risk factors), including both HF subtypes (HF with preserved LVEF: HR: 1.81; 95%CI: 1.17-2.80; P=0.0081, and HF with reduced LVEF: HR: 2.63; 95%CI: 1.48-4.68; P=0.0010, adjusted for age, sex, ASA use, and cardiovascular disease). Neither ASA use nor evidence of platelet activation, as measured by plasma P-selectin, were independently associated with HF risk. Systemic thromboxane A2 generation as measured by urinary TXB2-MGFR was significantly associated with HF risk and remained so after accounting for traditional risk factors. Urinary TXB2-MGFR is therefore a potentially useful novel biomarker to identify at-risk individuals who might benefit from aggressive primary prevention.

Association between endothelial microparticles and objectively measured physical activity in adults with obesity

BackgroundCardiovascular disease (CVD) is a serious global public health concern that often originates from endothelial dysfunction. Microparticles (MPs) can reflect alterations in tissue or cell function phenotype and responsiveness under various physiological and pathological conditions. MPs derived from endothelial cells may serve as potential biomarkers for CVD. We investigated the association between endothelial-derived MPs (EMPs) and objectively measured physical activity (PA) in adults with obesity and their potential correlation with inflammatory and cardiometabolic biomarkers. MethodsThis cross-sectional study included 50 participants, whose daily movement behaviors were evaluated using activPAL™, which measures moderate-to-vigorous intensity PA (MVPA), light PA (LPA), and standing time. The MP sub-populations were separated from platelet-poor plasma, incubated with multiple antibodies, and analyzed using multi-color flow cytometry. Cytokines, interleukin (IL)−1β, IL-8, E-selectin, P-selectin, and intercellular adhesion molecules (ICAMs), were measured using a customized Luminex® assay kit. Pearson’s correlation coefficients were used to examine associations. ResultsMVPA was associated with lower expressions of ICAM and E-selectin in EMPs, whereas standing time was associated with a higher expression of E-selectin. A positive association exists between leukocyte-derived MP percentage and P-selectin levels in EMPs and E-selectin levels in the plasma. In addition, higher plasma P-selectin level was associated with higher P- and E-selectin levels in EMPs, as was higher inflammation (IL-1β and IL-8). ConclusionThe MPs were negatively associated with MVPA and positively associated with standing time in the participants with obesity. These results underscore the importance of promoting PA interventions, especially at moderate-to-vigorous intensities. Further longitudinal and interventional studies are warranted to elucidate the dynamic interplay among PA, MPs, and endothelial function.

Zixue Powder attenuates septic thrombosis via reducing neutrophil extracellular trap through blocking platelet STING activation

Ethnopharmacological relevanceMicrothrombosis is commonly seen in sepsis and COVID-19. Zixue Powder (ZXP) is a traditional Chinese herbal formula with the potential to treat microvascular and infectious diseases. However, the role and mechanism of ZXP in sepsis-associated thrombosis remain unclear. Aim of the studyInvestigating the therapeutic effectiveness and underlying mechanisms of ZXP in septic thrombosis. Materials and methodsZXP's compositions were examined with UPLC-QTOF-MS. The efficacy of ZXP on sepsis-induced thrombosis was assessed through various methods: liver tissue pathology was examined using hematoxylin-eosin staining, platelet count was determined by a blood cell analyzer, and an enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of serum tissue factor (TF), thromboxane B2 (TXB2), D-Dimer, and plasminogen activator inhibitor-1 (PAI-1). Neutrophil extracellular traps (NETs) were localized and expressed in liver tissues by immunofluorescence, and the number of NETs in peripheral blood was evaluated by ELISA, which measured the quantity of cf-DNA and MPO-DNA in serum. Platelet P-selectin expression and platelet-neutrophil aggregation were measured by flow cytometry, and plasma P-selectin expression was measured by ELISA. Furthermore, the mechanism of the stimulator of interferon genes (STING) signaling pathway in ZXP's anti-sepsis thrombosis effect was investigated using the STING agonist, Western blot experiments, and immunoprecipitation experiments. ResultsUPLC-QTOF-MS identified 40 chemical compositions of ZXP. Administration of ZXP resulted in significant improvements in liver thrombosis, platelet counts, and levels of TXB2, TF, PAI-1, and D-Dimer in septic rats. Moreover, ZXP inhibited NETs formation in both liver tissue and peripheral blood. Additionally, ZXP decreased the levels of P-selectin in both platelets and plasma, as well as the formation of platelet-neutrophil aggregates, thereby suppressing P-selectin-mediated NETs release. Immunoprecipitation and immunofluorescence staining experiments revealed that ZXP attenuated P-selectin secretion by inhibiting STING-mediated assembly of platelet soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) complex, ultimately preventing inhibition of NETs formation. ConclusionOur study showed that ZXP effectively mitigates platelet granule secretion primarily through modulation of the STING pathway, consequently impeding NET-associated thrombosis in sepsis. These findings offer valuable insights for future research on the development and application of ZXP.

Evaluation of Clinical Risk Factors and Thrombosis-Related Biomarkers in Newly Diagnosed Patients with Multiple Myeloma at Risk for Cancer-Associated Thrombosis. the Observational Roadmat-CAT-MM Study

Background: Hypercoagulability is a common blood alteration in newly diagnosed chemotherapy naïve patients with multiple myeloma. Multiple myeloma (MM) figures among malignancies that significantly increase the risk of venous thromboembolism (VTE). The rate of VTE is higher at the time of diagnosis and during the first months following initiation of first line therapy; approximately 10% of newly diagnosed MM (NDMM) will develop a VTE. Despite adequate thromboprophylaxis as per guidelines, the risk of residual VTE is not eliminated and remains as high as 12%. The optimization of VTE prevention in patients with MM is an unmet need. The exact mechanism of the increased risk of VTE is not yet fully understood. The identification of the procoagulant potential of cancer cells, which is related principally to tissue factor (TF) expression, attracts particular interest. Aim: We conducted a longitudinal prospective observational study, to explore the relationship of MM with cellular and plasma hypercoagulability as well as tissue factor positive microparticles, aiming to identify the most relevant biomarkers, which could be used in a Risk Assessment Model (RAM) for VTE in combination with clinical risk factors. Methods: Newly diagnosed patients (182) with multiple myeloma (NDMM) were prospectively enrolled. Patients were followed up for 12 months and the primary end-point was symptomatic objectively confirmed VTE. Patients were risk stratified and received thromboprophylaxis (none, aspirin on low molecular weight heparin (LMWH) based on previously published recommendations by the IMWG and EMN. Prior to treatment initiation and thromboprophylaxis initiation baseline biomarkers were obtained: Thrombin generation (TGT) in citrated PPP was assessed with the Thrombogram-Thrombinoscope® assay using PPP-reagent® 5 pm TF by Diagnostica Stago. The levels of P-Selectin and heparanase in plasma were measured with ELISA Kit (Cusabio Biotech and R&amp;D Systems respectively). The procoagulant phospholipids clotting time was measured with STA-Procoag-PPL®, Levels of Factor VIIa were measured by Staclot VIIa-rTF®, D-Dimers (DDi) by Liatest D-Di (Diagnostica Stago, France), and Tissue Factor activity (TFa) by specific clotting based home test. TF expression MPC-derived microparticles (MPC-dMPs) were detected using a Zymuphen MP-TF activity kit (Hyphen BioMed, Neuville sur Oise, France). These were compared against values in a population of healthy individuals (n=30). Results: The distribution of patients enrolled in the study is as follows: Median age was 67 years (36-86) and 52% of the population was male. Median time to follow up was 7 months (1-12 months). The control group (30 healthy individuals). The overall rate of symptomatic VTE during follow-up was 11.5% (n = 21 patients). Eleven out of 21 events (52%) occurred within 3 months from treatment initiation. Six of these patients did not receive any thromboprophylaxis; six patients were on aspirin at the time of the event and three were on LMWH.At inclusion, patients showed significantly increased levels of TFa, FVIIa, D-Dimers and FM, and significantly shorter Procoag-PPL® as compared to the group of healthy individuals. Levels of P-selectin and TM were significantly lower in patients as compared to healthy individuals. The levels of heparanase were not significantly different in the group of patients as compared to the healthy individuals. Overall thrombin generation was attenuated in patients compared to healthy individuals. Lag-time and ttPeak were significantly increased and Peak, MRI, and ETP were significantly lower as compared to the control group, MP-TF activity measured in NDMM significantly increased 1.46± 0.38 pg/mL compared to control subjects 0.19 ± 0.05 pg/mL (Table 1). Multivariate logistic regression analysis demonstrated that ETP, Procoag-PPL® and MP-TF were independently associated with VTE occurrence. (Table 2) Conclusion: The prospective ROADMAP-CAT-MM study demonstrates the presence of pronounced cellular hypercoagulability in newly diagnosed chemotherapy naïve patients with MM characterized by decreased Procoag-PPL® clotting time, enhanced endothelial cell activation, and exhausted thrombin generation. The Procoag-PPL clotting time and the ETP and MP-TF were found to be independently associated with the risk of VTE and can be prospectively incorporated into a RAM for VTE in MM.

The roles of P-selectin in cancer cachexia.

P-selectin, a cell adhesion molecule of the selectin family, is expressed on the surface of activated endothelial cells (ECs) and platelets. Binding of P-selectin to P-selectin glycoprotein ligand-1 (PSGL-1) supports the leukocytes capture and rolling on stimulated ECs and increases the aggregation of leukocytes and activated platelets. Cancer cachexia is asystemic inflammation disorder characterized by metabolic disturbances, reduced body weight, loss ofappetite, fat depletion, and progressive muscle atrophy. Cachexia status is associated with increased pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α), which activates ECs to release P-selectin. Single-nucleotide polymorphisms (SNPs) loci of P-selectin encoding gene SELP are associated with higher level of plasma P-selectin and increase the susceptibility to cachexia in cancer patients. Elevated P-selectin expression has been observed in the hypothalamus, liver, and gastrocnemius muscle in animal models with cancer cachexia. Increased P-selectin may cause excessive inflammatory processes, muscle atrophy, and blood hypercoagulation, thus facilitating the development of cancer cachexia. In this review, physiological functions of P-selectin and its potential roles in cancer cachexia have been summarized. We also discuss the therapeutic potential of P-selectin inhibitors for the treatment of cancer cachexia.

Differential inhibition of platelet function by cilostazol in combination with clopidogrel.

To assess the antiplatelet effect of cilostazol clinically, we compared the effects of cilostazol in combination with clopidogrel on various platelet function tests. We recruited patients with ischemic stroke at high risk of recurrence who were treated with clopidogrel alone within 180days after stroke onset. Subjects underwent baseline platelet function tests, and were then randomly assigned to receive dual antiplatelet therapy (DAPT) comprising clopidogrel and cilostazol or clopidogrel monotherapy (SAPT). After 6months, platelet function was measured again and compared to that at baseline in each group, and the rate of change was compared between groups. Thirty-four patients were enrolled, but 4 patients were excluded for various reasons. In total, 30 subjects (13 in DAPT and 17 in SAPT group) were analyzed. Adenosine diphosphate- and collagen-induced aggregation, VerifyNow P2Y12 reaction units, vasodilator-stimulated phosphoprotein (platelet reactivity index: PRI) and plasma p-selectin concentration were significantly lower (P = 0.004, 0.042, 0.049, 0.003 and 0.006 respectively), while VerifyNow % inhibition was significantly higher at 6months compared to baseline (P = 0.003) in the DAPT group only. Comparison of the rate of change in each parameter from baseline to 6months showed that while PRI decreased at a greater rate (P = 0.012), VerifyNow % inhibition increased at a greater rate (P = 0.003) in the DAPT group than the SAPT group. The inhibitory effects of adjunctive cilostazol added to clopidogrel on platelet function differed by type of platelet function test. VerifyNow % inhibition and PRI were more inhibited than the other platelet function tests. CSPS.com substudy in TWMU (UMIN000026672), registered on April 1, 2017. This study was performed as a substudy of CSPS.com (UMIN000012180, registered on October 31, 2013) and was retrospectively registered.

Oral famotidine reduces the plasma level of soluble P-selectin in children with sickle cell disease.

Plasma histamine levels are increased in patients with sickle cell disease (SCD), potentially promoting endothelial P-selectin expression and vaso-occlusion via histamine type 2 (H2) receptors. We conducted a prospective, non-comparative, single-centre study to determine whether famotidine, a H2 receptor antagonist, reduces P-selectin expression in SCD children. The median plasma P-selectin level was significantly reduced after 29 days of oral famotidine (53.2 ng/mL [IQR: 46.7-63.4] vs. 69.9 ng/mL [IQR: 53.6-84.2], median difference -10.2 ng/mL [IQR: -21.8 to -2.7], p = 0.005) in 28 patients. No effect was observed on other adhesion molecules, inflammation or haemolysis markers, except decreased reticulocyte count. No adverse events deemed related to famotidine were observed. Randomized controlled trials are now needed to assess the efficacy of famotidine in preventing vaso-occlusion in SCD.

Plasma Interleukin-6 (IL-6), Angiopoietin-2, and C-Reactive Protein Levels Predict Subsequent Type 1 Myocardial Infarction in Persons With Treated HIV Infection.

HIV infection leads to endothelial activation, promoting platelet adhesion, and accelerating atherosclerosis. Our goal was to determine whether biomarkers of endothelial activation and hemostasis/thrombosis were elevated in people with treated HIV (PWH) before myocardial infarction (MI). In a case-control study nested within the CFAR Network of Integrated Clinical Systems (CNICS) cohort, we compared 69 adjudicated cases with type 1 MI with 138 controls matched for antiretroviral therapy regimen. We measured angiopoietin-1, angiopoietin-2 (ANG-2), intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS13), von Willebrand factor, C-reactive protein (CRP), interleukin-6 (IL-6), plasminogen activation inhibitor-1, P-selectin, serum amyloid-A, soluble CD14, and apolipoprotein A1 in stored plasma. Conditional logistic regression identified associations with subsequent MI, with and without adjustment for Atherosclerotic Cardiovascular Disease (ASCVD) and Veterans Aging Cohort Study (VACS) scores. Higher IL-6 was associated with MI after adjustment for ASCVD score (adjusted odds ratio [AOR] 1.51, 95% confidence interval [95% CI]: 1.05 to 2.17 per standard-deviation-scaled log 2 increment). In a separate model adjusting for VACS score, higher ANG-2 (AOR 1.49, 95% CI: 1.04 to 2.14), higher CRP (AOR 1.45, 95% CI: 1.06 to 2.00), and higher IL-6 (AOR 1.68, 95% CI: 1.17 to 2.41) were associated with MI. In a sensitivity analysis excluding PWH with viral load ≥400 copies/mL, higher IL-6 remained associated with MI after adjustment for ASCVD score and after adjustment for VACS score. Among PWH, higher levels of plasma IL-6, CRP, and ANG-2 predict subsequent type 1 MI, independent of conventional risk scores. IL-6 had the most consistent associations with type 1 MI, regardless of viral load suppression.

Plasma levels of P-selectin and future risk of incident venous thromboembolism

BackgroundP-selectin levels are elevated following acute deep vein thrombosis and reported to predict recurrent venous thromboembolism (VTE) and cancer-associated VTE. Yet, it is unknown whether plasma P-selectin levels are associated with incident VTE. ObjectivesWe aimed to investigate the association between plasma P-selectin levels and risk of future incident VTE. MethodsWe performed a nested case-control study in 415 patients with VTE and 843 age- and sex-matched controls derived from the general population (Tromsø IV Study). Plasma P-selectin levels were measured using enzyme-linked immunosorbent assay. Logistic regression models were used to estimate odds ratios (ORs) for VTE across quartiles of plasma P-selectin level. Sex-stratified analysis was also performed. ResultsPlasma P-selectin levels were higher in men (41.4 ng/mL) than in women (38.7 ng/mL, p = .0046). We found no association between plasma P-selectin levels and risk of VTE in the overall analyses. However, sex-stratified analyses revealed that women with P-selectin levels in the highest quartile (>44.3 ng/mL) had higher risk of VTE (OR, 1.63; 95% CI, 1.01-2.64) than women with P-selectin levels in the lowest quartile (≤29.9 ng/mL). In contrast, higher levels of P-selectin were apparently associated with lower risk of VTE in men (OR for highest vs lowest quartile of P-selectin, 0.69; 95% CI, 0.42-1.15). The observed associations were stronger when the time between blood sampling and VTE was shorter. ConclusionElevated levels of plasma P-selectin were associated with increased risk of VTE in women but not in men, suggesting a differential impact of sex on the association between P-selectin and VTE risk.

Plasma P-selectin is an early marker of thromboembolism in COVID-19

Plasma P-selectin is an early marker of thromboembolism in COVID-19

Plasma IGFBP-1, Fas, kallistatin, and P-selectin as predictive biomarkers of histologic chorioamnionitis and associated intra-amniotic infection in women with preterm labor.

To determine whether altered levels of 13 plasma biomarkers, alone or in combination, could be independently associated with histologic chorioamnionitis (HCA) and microbial-associated HCA (defined as the presence of HCA along with microbial invasion) in women with preterm labor (PTL). This was a retrospective cohort study involving 77 singleton pregnant women with PTL (23-34 gestational weeks) who delivered within 96h of plasma and amniotic fluid (AF) sampling. DKK-3, E-selectin, Fas, haptoglobin, IGFBP-1, kallistatin, MMP-2, MMP-8, pentraxin 3, progranulin, P-selectin, SAA4, and TGFBI levels were assayed in plasma samples by ELISA. AF obtained via amniocentesis was used for microorganism identification. Multiple logistic regression analyses revealed significant associations between low plasma IGFBP-1 levels and acute HCA, and between low plasma Fas and kallistatin levels, and elevated plasma P-selectin levels and microbial-associated HCA (all p<.05), after adjusting for gestational age. Using a stepwise regression procedure, a multi-biomarker panel for microbial-associated HCA was developed, which included plasma MMP-2, kallistatin, and P-selectin levels (area under the curve [AUC], .867). The AUC for this three-marker panel was significantly or borderline significantly greater than that of any single variable included in the panel. However, a predictive model for acute HCA could not be developed because only one variable (MMP-2) was selected. These findings demonstrate that IGFBP-1, Fas, kallistatin, and P-selectin are associated with acute HCA and microbial-associated HCA in women with PTL. Their combined use can significantly improve the diagnostic ability for the detection of microbial-associated HCA.

Ruscogenin Alleviates Deep Venous Thrombosis and Pulmonary Embolism Induced by Inferior Vena Cava Stenosis Inhibiting MEK/ERK/Egr-1/TF Signaling Pathway in Mice.

Ruscogenin (RUS) has anti-inflammatory and antithrombotic effects, while its potential effects on deep venous thrombosis (DVT) and pulmonary embolism (PE) remain unclear. We aimed to elucidate the effects of RUS on DVT and PE induced by the inferior vena cava stenosis (IVCS) model and investigate the underlying mechanism. Male C57/BL6 mice were used to explore whether IVCS model could be complicated with deep venous thrombosis and pulmonary embolism. Then, effects of RUS on DVT and PE related inflammatory factors and coagulation were examined using H&E staining, ELISA, and real-time PCR. Western blot analysis was used to examine the effects of RUS on MEK/ERK/Egr-1/TF signaling pathway in PE. IVCS model induced DVT and complied with PE 48 h after surgery. Administration of RUS (0.01, 0.1, 1 mg/kg) inhibited DVT, decreased biomarker D-Dimer, cardiac troponin I, N-Terminal probrain natriuretic peptide in plasma to ameliorate PE induced by IVCS model. Meanwhile, RUS reduced tissue factor and fibrinogen content of lung tissue, inhibited P-selectin and C-reactive protein activity in plasma, and suppressed the expressions of interleukin-6 and interleukin-1β in mice. Furthermore, RUS suppressed the phosphorylation of ERK1/2 and MEK1/2, decreasing the expressions of Egr-1 and TF in the lung. IVCS model contributed to the development of DVT and PE in mice and was associated with increased inflammation. RUS showed therapeutic effects by inhibiting inflammation as well as suppressing the activation of MEK/ERK/Egr-1/TF signaling pathway.

SARS-CoV-2 infection induces soluble platelet activation markers and PAI-1 in the early moderate stage of COVID-19.

IntroductionCoagulation dysfunction and thromboembolism emerge as strong comorbidity factors in severe COVID‐19. However, it is unclear when particularly platelet activation markers and coagulation factors dysregulated during the pathogenesis of COVID‐19. Here, we sought to assess the levels of coagulation and platelet activation markers at moderate and severe stages of COVID‐19 to understand the pathogenesis.MethodsTo understand this, hospitalized COVID‐19 patients with (severe cases that required intensive care) or without pneumonia (moderate cases) were recruited. Phenotypic and molecular characterizations were performed employing basic coagulation tests including prothrombin time (PT), activated partial thromboplastin time (APTT), D‐Dimer, and tissue factor pathway inhibitor (TFPI). The flow cytometry‐based multiplex assays were performed to assess FXI, anti‐thrombin, prothrombin, fibrinogen, FXIII, P‐selectin, sCD40L, plasminogen, tissue plasminogen activator (tPA), plasminogen activator inhibitor‐1 (PAI‐1), and D‐Dimer.ResultsThe investigations revealed induction of plasma P‐selectin and CD40 ligand (sCD40L) in moderate COVID‐19 cases, which were significantly abolished with the progression of COVID‐19 severity. Moreover, a profound reduction in plasma tissue factor pathway inhibitor (TFPI) and FXIII were identified particularly in the severe COVID‐19. Further analysis revealed fibrinogen induction in both moderate and severe patients. Interestingly, an elevated PAI‐1 more prominently in moderate, and tPA particularly in severe COVID‐19 cases were observed. Particularly, the levels of fibrinogen and tPA directly correlated with the severity of the disease.ConclusionsIn summary, induction of soluble P‐selectin, sCD40L, fibrinogen, and PAI‐1 suggests the activation of platelets and coagulation system at the moderate stage before COVID‐19 patients require intensive care. These findings would help in designing better thromboprophylaxis to limit the COVID‐19 severity.

Soluble P-Selectin and von Willebrand Factor Rise in Healthy Volunteers Following Non-exertional Ascent to High Altitude.

Reduced oxygen tensions experienced at high altitudes are thought to predispose to thrombosis, yet there are few studies linking hypoxia, platelet activation, and thrombosis. Reports of platelet phenotypes in hypoxia are inconsistent, perhaps due to differing degrees of hypoxia experienced and the duration of exposure. This study aimed to investigate the relationship between soluble P-selectin, a marker of platelet activation, and von Willebrand factor (vWF) on exposure to hypoxia. We measured plasma concentrations of P-selectin and vWF in sixteen healthy volunteers before, during and after the APEX 2 expedition. APEX 2 consisted of a non-exertional ascent to 5,200 m, followed by 7 consecutive days at high altitude. We showed that high altitude significantly increased mean plasma P-selectin and vWF compared to pre-expedition levels. Both plasma marker levels returned to baseline post-expedition. We found a strong positive correlation between vWF and P-selectin, but no association between P-selectin and platelet count. Our results are consistent with previous work showing evidence of platelet activation at high altitude and demonstrate that the rise in P-selectin is not simply due to an increase in platelet count. As vWF and P-selectin could be derived from either platelets or endothelial cells, further work assessing more specific markers of endothelial activation is proposed to provide insight into the source of these potential pro-thrombotic biomarkers at altitude.

Pleiotropic vascular effects of ivabradine in streptozotocin-induced diabetes

AimsIvabradine (IVA) reduces heart rate (HR) by inhibiting hyperpolarization-activated cyclic nucleotide-gated (HCN) channels in sinoatrial node. Studies suggest that IVA has other beneficial effects on cardiovascular system that are not related to its effect on HR such as prevention of endothelial injury and the antioxidant effects. In addition to sinoatrial node, HCN channels exist in other tissues and their expression pattern differs in certain pathologies such as hypertension and hypertrophy. We investigated the mechanism of IVA effect in the setting of streptozotocin (STZ)-induced cardiovascular damage. Direct effects of IVA and their mechanism on thoracic aorta as well as possible prevention of vascular dysfunction in diabetes were investigated in this study. Methods and resultsThe effects of IVA on vascular function were investigated in control and STZ-diabetic rats. Some control and diabetic rats were treated with IVA. IVA treatment prevented diabetes-induced increase in plasma p-selectin and vascular cell adhesion molecule-1 levels and the decrease in nitric oxide content in the aortas of diabetic animals. When added to isolated organ bath, IVA induced concentration-dependent relaxations in thoracic aorta. Pre-incubation with Nω-Nitro- L -arginine methyl ester reduced IVA-induced relaxations. Expression patterns of all isoforms of HCN proteins were affected by both diabetes and IVA treatment. ConclusionIVA improves vascular function in diabetes and HCN channels support vascular activity against damaging effects of diabetes. IVA may be added to prevent diabetic cardiovascular dysfunction with these beneficial effects that are unrelated to its primary mechanism of action.

Effect of Tai Chi Chuan practice on immune system and pro-metastasis markers in early post-treatment breast cancer survivors

Purpose: To investigate the effect of Tai Chi Chuan (TCC) to improve immune system and decrease pro-metastasis markers in early post-treatment breast cancer survivors. Methods: 130 post-treatment breast cancer survivors were recruited and randomized 1:1 into TCC group and wait-list (control) group. The TCC group practiced for a 60-minutes session once per week, for a total of 52 weeks. 115 forms of Yang-style TCC were taught by a Tai Chi master. Blood samples were taken from each subject and complete blood count was performed. The expressions of NKG2D protein, P-selectin, and vascular endothelial growth factor (VEGF) in plasma were measured. Lymphocyte activity was measured by cell proliferation reagent and ATP assay. Images of lymphocyte colony formation were taken with an inverted microscope. Results: At 52 weeks, TCC group demonstrated a significantly higher WBC (p=0.001) , a significantly higher NKG2D value (p=0.001) and a significantly lower VEGF value (p=0.005) when compared to the wait-list group. However, there was a small, non-significant change for P-selectin values between the breast cancer survivor groups. After 72h incubation, TCC group had a significant increase in lymphocyte proliferation (p=0.001) and greater area of lymphocyte clusters or colonies (p=0.001). Conclusion: The practice of TCC could stimulate tumor immunosurveillance via NKG2D and activate the immune response. VEGF, a marker playing an important role in breast cancer and its metastases, was also reduced in those who practiced TCC. As an alternative for conventional exercise, post-treatment breast cancer survivors may select TCC in their rehabilitation program.

Rivaroxaban compared with low-dose aspirin in individuals with type 2 diabetes and high cardiovascular risk: a randomised trial to assess effects on endothelial function, platelet activation and vascular biomarkers

Aims/hypothesisIndividuals with type 2 diabetes mellitus and subclinical inflammation have stimulated coagulation, activated platelets and endothelial dysfunction. Recent studies with the direct factor Xa inhibitor rivaroxaban in combination with low-dose aspirin demonstrated a significant reduction of major cardiovascular events, especially in individuals with type 2 diabetes and proven cardiovascular disease. Therefore, we asked the question of whether treatment with rivaroxaban could influence endothelial function, arterial stiffness and platelet activation.MethodsWe conducted a multi-centre, prospective, randomised, open-label trial in 179 participants with type 2 diabetes (duration 2–20 years), subclinical inflammation (high-sensitivity C-reactive protein 2–10 mg/l) and at least two traits of the metabolic syndrome to compare the effects of the direct factor Xa inhibitor rivaroxaban (5 mg twice daily) vs aspirin (100 mg every day) on endothelial function (assessed by forearm occlusion plethysmography), skin blood flow (assessed by laser-Doppler fluxmetry), arterial stiffness (assessed by pulse wave velocity) and serum biomarkers of endothelial function and inflammation. Furthermore, we investigated phosphorylation of vasodilator-stimulated phosphoprotein (VASP) in platelets, the concentration of platelet-derived microparticles (PMPs) and the effects of isolated PMPs on HUVEC proliferation in vitro.ResultsRivaroxaban treatment for 20 weeks (n = 89) resulted in a significant improvement of post-ischaemic forearm blood flow (3.6 ± 4.7 vs 1.0 ± 5.2 ml/100 ml, p = 0.004), a numerically increased skin blood flow and reduced soluble P-Selectin plasma level vs aspirin. We did not find significant differences of arterial stiffness or further biomarkers. Neither rivaroxaban nor aspirin influenced VASP phosphorylation of platelets. The number of PMPs increased significantly with both rivaroxaban (365.2 ± 372.1 vs 237.4 ± 157.1 μl−1, p = 0.005) and aspirin (266.0 ± 212.7 vs 201.7 ± 162.7 μl−1, p = 0.021). PMPs of rivaroxaban-treated participants stimulated HUVEC proliferation in vitro compared with aspirin. Rivaroxaban was associated with a higher number of bleeding events.Conclusions/interpretationOur findings indicate that the direct factor Xa inhibitor rivaroxaban improved endothelial function in participants with type 2 diabetes and subclinical inflammation but also increased the risk of bleeding.Trial registration:ClinicalTrials.gov NCT02164578.FundingThe study was supported by a research grant from Bayer Vital AG, Germany.Graphical abstract

Abstract P357: Induction Of Soluble P-selectin And CD40 Ligand And, FXIII Deficiency Promote Aberrant Coagulation And Thromboembolism In Severe COVID-19

Coagulation dysfunction and thromboembolism emerge as strong comorbidity factors in severe COVID-19. However, the underlying pathomechanisms are largely undefined. Here, we sought to identify the potential underlying molecular mechanisms of SARS-CoV-2 mediated coagulopathy and thromboembolism. In this series, 30 hospitalized COVID-19 patients presenting elevated D-dimer with (severe cases that required intensive care) or without pneumonia (moderate cases) were included in the study. Patients with anticoagulant/ antiplatelet therapy or with a history of cardiovascular diseases were excluded. Phenotypic and molecular characterizations were carried out employing basic coagulation tests, flow cytometry-based multiplex assays, and ELISA. The findings revealed slightly higher prothrombin and activated partial thromboplastin times (aPTT) with normal platelet counts. Elevated levels of plasma P-selectin and CD40 ligand (CD40L), markers of platelet activation, were observed in the moderate COVID-19 cases which were significantly abolished with the progression of COVID-19 severity. Moreover, analysis of the coagulation pathways revealed comparable FIX, prothrombin, and anti-thrombin levels, and a significantly higher level of fibrinogen was observed in both the moderate and severe patients vs. control group. Interestingly, the levels of plasma tissue factor pathway inhibitor (TFPI) and FXIII, a regulator of stable thrombus formation, were significantly lower particularly in the severe COVID-19 cases. Moreover, a dysregulated fibrinolysis was indicated by elevated tissue plasminogen activator (tPA), plasminogen activator inhibitor (PAI), and D-dimer levels in COVID-19 cases. In summary, SARS-CoV-2 infection-mediated endothelial cell lining damage potentially enhances soluble P-selectin and CD40L levels inducing platelet activation. Furthermore, in severe COVID-19, a decreased level of TFPI possibly contributes to additional thrombin generation through activation of the TF pathway and provides positive feedback to platelet activation and thrombus formation. FXIII deficiency plays a key role in thrombus instability which most likely promotes thromboembolism in the severe COVID-19.

Plasma P-selectin is a predictor of mortality in heart failure with preserved ejection fraction.

AimsThe aim of the study was to assess the association of P‐selectin with outcomes in heart failure with preserved ejection fraction (HFpEF).Methods and resultsThis is a prospective, observational study of 130 HFpEF patients who underwent clinical profiling, blood sampling, 6 min walk testing, Minnesota Living with Heart Failure Questionnaire evaluation, echocardiography, cardiovascular magnetic resonance imaging, calculation of the Meta‐Analysis Global Group in Chronic Heart Failure (MAGGIC) risk scores, and blinded plasma P‐selectin measurement. Patients were followed up for the endpoint of all‐cause mortality. The HFpEF subgroup with higher P‐selectin levels [overall median 26 372, inter‐quartile range (19 360–34 889) pg/mL] was associated with lower age, higher heart rate, less prevalent atrial fibrillation, more frequent current smoking status, and lower right ventricular end‐diastolic volumes. During follow‐up (median 1428 days), there were 38 deaths. Following maximal sensitivity and specificity receiver operating characteristic curve analysis, P‐selectin levels above 35 506 pg/mL were associated with greater risk of all‐cause mortality [hazard ratio (HR) 2.700; 95% confidence interval (CI) 1.416–5.146; log‐rank P = 0.002]. Following multivariable Cox proportional hazards regression analysis and when added to MAGGIC scores, only P‐selectin (adjusted HR 1.707; 95% CI 1.099–2.650; P < 0.017) and myocardial infarction detected by cardiovascular magnetic resonance imaging (HR 2.377; 95% CI 1.114–5.075; P < 0.025) remained significant predictors. In a final model comprising all three parameters, only P‐selectin (HR 1.447; 95% CI 1.130–1.853; P < 0.003) and MAGGIC scores (HR 1.555; 95% CI 1.136–2.129; P < 0.006) remained independent predictors of death. Adding P‐selectin (0.618, P = 0.035) improved the area under the receiver operating characteristic curve for mortality prediction for MAGGIC scores (0.647, P = 0.009) to 0.710, P < 0.0001.ConclusionsPlasma P‐selectin is an independent predictor of mortality and provides incremental prognostic information beyond MAGGIC scores in HFpEF.

Elevated P-Selectin in Severe Covid-19: Considerations for Therapeutic Options.

BackgroundCoronavirus disease 2019 (COVID-19) is mainly a respiratory tract disease and acute respiratory failure with diffuse microvascular pulmonary thrombosis are critical aspects of the morbidity and mortality of this new syndrome.PurposeThe aim of our study was to investigate, in severe COVID-19 hospitalized patients, the P-selectin plasma concentration as a biomarker of endothelial dysfunction and platelet activation.Methods46 patients with severe or critical SARS-CoV-2 infection were included in the study. Age-matched patients then were divided in those requiring admission to the intensive care unit (ICU, ICU cases) vs those not requiring ICU hospitalization (non-ICU cases). Blood samples of severe COVID-19 patients were collected at the time of hospital admission. The quantification of soluble P-selectin was performed by ELI, assay.ResultsOur study showed a higher P-selectin plasma concentration in patients with Covid-19, regardless of ICU admission, compared to the normal reference values and compared to ten contextually sampled healthy donors (HD); (COVID-19): median 65.2 (IQRs: 45.1–81.1) vs. HD: 40.3 (IQRs: 24.3–48.7), p=0023. Moreover, results showed a significant reduction of P-sele din after platelets removal in HD, in contrast, both ICU and non-ICU COVID-19 patients showed similar high levels of P-selectin with and without platelets.ConclusionElevation of P-selectin suggests a central role of platelet endothelium interaction as part of the multifaced pathogenic mechanism of COVID-19 leading to the local activation of hemostatic system forming pulmonary thrombi. Further work is necessary to determine the therapeutic role of antiplatelets agents or of the anti P-selectin antibody Crizanlizumab.