<div><h4>Altered whole blood thrombin generation and hyperresponsive platelets in patients with pancreatic cancer.</h4><i>Willems RAL, Konings J, Huskens D, Middelveld H, ... de Laat B, Roest M</i><br /><b>Background</b><br />Thromboembolic disease is a major complication in patients with pancreatic ductal adenocarcinoma (PDAC). Patients with PDAC often have altered blood cell counts, which are associated with venous thromboembolism (VTE) development. The high thrombotic risk in patients with PDAC may be partially caused by procoagulant blood cells.<br /><b>Objectives</b><br />The aim of this study was to compare blood cell-dependent coagulation between patients with PDAC (n = 18) and healthy controls matched for age and sex (n = 18).<br /><b>Methods</b><br />Thrombin generation (TG) was measured in whole blood (WB) and plasma. The capacity of platelets to release granules (PGRCs) was measured in WB. We explored the occurrence of thromboembolic events in patients with PDAC during a 6-month follow-up.<br /><b>Results</b><br />Patients showed an increased endogenous thrombin potential in WB compared with controls. This difference was not observed in plasma, indicating a procoagulant effect of blood cells. Both in WB and plasma, the lag time was prolonged in patients compared with controls. Patients had hyperresponsive platelets, with a shorter time to peak granule release. Of the 18 patients with PDAC, 4 developed a venous thromboembolism (22%) and 1 developed an arterial thrombosis (6%). A shorter lag time in WB, but not in plasma, and an increased PGRC were associated with thromboembolic events.<br /><b>Conclusion</b><br />Patients with PDAC have an increased and delayed WB TG coagulation profile compared with controls. A shorter lag time in WB TG and increased PGRC are associated with the incidence of thromboembolic events. Platelets appear to be key players in thrombosis development. Measuring hemostasis in WB could improve thrombosis risk estimation in patients with PDAC.<br /><br />Copyright © 2024 International Society on Thrombosis and Haemostasis. Published by Elsevier Inc. All rights reserved.<br /><br /><small>J Thromb Haemost: 01 Apr 2024; 22:1132-1144</small></div>

<div><h4>Density-based lipoprotein depletion improves extracellular vesicle isolation and functional analysis.</h4><i>Merij LB, da Silva LR, Palhinha L, Gomes MT, ... de Oliveira Trugilho MR, Hottz ED</i><br /><b>Background</b><br />Blood plasma is the main source of extracellular vesicles (EVs) in clinical studies aiming to identify biomarkers and to investigate pathophysiological processes, especially regarding EV roles in inflammation and thrombosis. However, EV isolation from plasma has faced the fundamental issue of lipoprotein contamination, representing an important bias since lipoproteins are highly abundant and modulate cell signaling, metabolism, and thromboinflammation.<br /><b>Objectives</b><br />Here, we aimed to isolate plasma EVs after depleting lipoproteins, thereby improving sample purity and EV thromboinflammatory analysis.<br /><b>Methods</b><br />Density-based gradient ultracentrifugation (G-UC) was used for lipoprotein depletion before EV isolation from plasma through size-exclusion chromatography (SEC) or serial centrifugation (SC). Recovered EVs were analyzed by size, concentration, cellular source, ultrastructure, and bottom-up proteomics.<br /><b>Results</b><br />G-UC efficiently separated lipoproteins from the plasma, allowing subsequent EV isolation through SEC or SC. Combined analysis from EV proteomics, cholesterol quantification, and apoB-100 detection confirmed the significant reduction in lipoproteins from isolated EVs. Proteomic analysis identified similar gene ontology and cellular components in EVs, regardless of lipoprotein depletion, which was consistent with similar EV cellular sources, size, and ultrastructure by flow cytometry and transmission electron microscopy. Importantly, lipoprotein depletion increased the detection of less abundant proteins in EV proteome and enhanced thromboinflammatory responses of platelets and monocytes stimulated in vitro with EV isolates.<br /><b>Conclusion</b><br />Combination of G-UC+SEC significantly reduced EV lipoprotein contamination without interfering in EV cellular source, gene ontology, and ultrastructure, allowing the recovery of highly pure EVs with potential implications for functional assays and proteomic and lipidomic analyses.<br /><br />Copyright © 2024 International Society on Thrombosis and Haemostasis. Published by Elsevier Inc. All rights reserved.<br /><br /><small>J Thromb Haemost: 01 May 2024; 22:1372-1388</small></div>

<div><h4>A new look at an old body: molecular determinants of Weibel-Palade body composition and von Willebrand factor exocytosis.</h4><i>Hordijk S, Carter T, Bierings R</i><br /><AbstractText>Endothelial cells, forming a monolayer along blood vessels, intricately regulate vascular hemostasis, inflammatory responses, and angiogenesis. A key determinant of these functions is the controlled secretion of Weibel-Palade bodies (WPBs), which are specialized endothelial storage organelles housing a presynthesized pool of the hemostatic protein von Willebrand factor and various other hemostatic, inflammatory, angiogenic, and vasoactive mediators. This review delves into recent mechanistic insights into WPB biology, including the biogenesis that results in their unique morphology, the acquisition of intraluminal vesicles and other cargo, and the contribution of proton pumps to organelle acidification. Additionally, in light of a number of proteomic approaches to unravel the regulatory networks that control WPB formation and secretion, we provide a comprehensive overview of the WPB exocytotic machinery, including their molecular and cellular mechanisms.</AbstractText><br /><br />Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.<br /><br /><small>J Thromb Haemost: 01 May 2024; 22:1290-1303</small></div>

<div><h4>Long-term simulated microgravity fosters carotid aging-like changes via Piezo1.</h4><i>Zhang J, Wang X, Fu Z, Xing C, ... Li J, Gao F</i><br /><b>Aims</b><br />Elucidating the impacts of long-term spaceflight on cardiovascular health is urgently needed in face of the rapid development of human space exploration. Recent reports including the NASA Twins Study on vascular deconditioning and aging of astronauts in spaceflight are controversial. The aims of this study were to elucidate whether long-term microgravity promotes vascular aging and the underlying mechanisms.<br /><b>Methods and results</b><br />Hindlimb unloading (HU) by tail suspension was used to simulate microgravity in rats and mice. The dynamic changes of carotid stiffness in rats during 8 weeks of HU were determined. Simulated microgravity led to carotid artery aging-like changes as evidenced by increased stiffness, thickness, fibrosis, and elevated senescence biomarkers in the HU rats. Specific deletion of the mechanotransducer Piezo1 in vascular smooth muscles significantly blunted these aging-like changes in mice. Mechanistically, mechanical stretch-induced activation of Piezo1 elevated microRNA-582-5p in vascular smooth muscle cells, with resultant enhanced synthetic cell phenotype and increased collagen deposition via PTEN/PI3K/Akt signalling. Importantly, inhibition of miRNA-582-5p alleviated carotid fibrosis and stiffness not only in HU rats but also in aged rats.<br /><b>Conclusions</b><br />Long-term simulated microgravity induces carotid aging-like changes via the mechanotransducer Piezo1-initiated and miRNA-mediated mechanism.<br /><br />© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.<br /><br /><small>Cardiovasc Res: 30 Apr 2024; 120:548-559</small></div>

<div><h4>A dispensable role of oligodendrocyte-derived laminin-α5 in brain homeostasis and intracerebral hemorrhage.</h4><i>Kang M, Nirwane A, Ruan J, Adithan A, ... Xu L, Yao Y</i><br /><AbstractText>Laminin, a major component of the basal lamina in the CNS, is also expressed in oligodendrocytes (OLs). However, the function of OL-derived laminin remains largely unknown. Here, we performed loss-of-function studies using two OL-specific laminin-α5 conditional knockout mouse lines. Both mutants were grossly normal and displayed intact blood-brain barrier (BBB) integrity. In a mouse model of intracerebral hemorrhage (ICH), control mice and both mutants exhibited comparable hematoma size and neurological dysfunction. In addition, similar levels of hemoglobin and IgG leakage were detected in the mutant brains compared to the controls, indicating comparable BBB damage. Consistent with this finding, subsequent studies revealed no differences in tight junction protein (TJP) and caveolin-1 expression among control and knockout mice, suggesting that neither paracellular nor transcellular mechanism was affected in the mutants. Furthermore, compared to the controls, both mutant lines showed comparable oligodendrocyte number, oligodendrocyte proliferation rate, MBP/MAG levels, and SMI-32 expression, highlighting a minimal role of OL-derived laminin-α5 in OL biology. Together, these findings highlight a dispensable role of OL-derived laminin-α5 in both brain homeostasis and ICH pathogenesis.</AbstractText><br /><br /><br /><br /><small>J Cereb Blood Flow Metab: 01 Apr 2024; 44:611-623</small></div>