Search results for "thrombosis"

Cumulative visual impact of two coagulability disorders: A case report.

2020

Cumulative visual impact of two coagulability disorders were reviewed by presenting a case of a young female patient with a spontaneous abortion and two thromboembolic events in 8 years, whose visual function was severely affected. The particularities of her genetic constellation regarding the retinal circulation are also discussed. The patient developed a central retinal artery occlusion in the right eye during pregnancy in 2010, which led to an extended hematological workup that revealed presence of MTHFR C677T and MTHFR A1298C heterozygote mutations. The screening for myeloproliferative disorders showed JAK2 V617F gene mutation. Test results confirmed the diagnosis of thrombophilia and e…

Identification of the integrin-binding site on coagulation factor VIIa required for proangiogenic PAR2 signaling.

2018

The tissue factor (TF) pathway serves both hemostasis and cell signaling, but how cells control these divergent functions of TF remains incompletely understood. TF is the receptor and scaffold of coagulation proteases cleaving protease-activated receptor 2 (PAR2) that plays pivotal roles in angiogenesis and tumor development. Here we demonstrate that coagulation factor VIIa (FVIIa) elicits TF cytoplasmic domain-dependent proangiogenic cell signaling independent of the alternative PAR2 activator matriptase. We identify a Lys-Gly-Glu (KGE) integrin-binding motif in the FVIIa protease domain that is required for association of the TF-FVIIa complex with the active conformer of integrin β1. A po…

Tissue factor at the crossroad of coagulation and cell signaling

2018

The tissue factor (TF) pathway plays a central role in hemostasis and thrombo-inflammatory diseases. Although structure-function relationships of the TF initiation complex are elucidated, new facets of the dynamic regulation of TF?s activities on cells continue to emerge. Cellular pathways that render TF non-coagulant participate in signaling of distinct TF complexes with associated proteases through the protease-activated receptor (PAR) family of G-protein coupled receptors. Additional coreceptors, including the endothelial protein C receptor (EPCR) and integrins, confer signaling specificity by directing subcellular localization and trafficking. We here review how TF is switchedbetween it…

2021

Every organism has an intrinsic biological rhythm that orchestrates biological processes in adjusting to daily environmental changes. Circadian rhythms are maintained by networks of molecular clocks throughout the core and peripheral tissues, including immune cells, blood vessels, and perivascular adipose tissues. Recent findings have suggested strong correlations between the circadian clock and cardiovascular diseases. Desynchronization between the circadian rhythm and body metabolism contributes to the development of cardiovascular diseases including arteriosclerosis and thrombosis. Circadian rhythms are involved in controlling inflammatory processes and metabolisms, which can influence t…

Large-scale identification of functional microRNA targeting reveals cooperative regulation of the hemostatic system.

2018

Essentials MicroRNAs (miRNAs) regulate the molecular networks controlling biological functions such as hemostasis. We utilized novel methods to analyze miRNA-mediated regulation of the hemostatic system. 52 specific miRNA interactions with 11 key hemostatic associated genes were identified. Functionality and drugability of miRNA-19b-3p against antithrombin were demonstrated in vivo. SUMMARY: Background microRNAs (miRNAs) confer robustness to complex molecular networks regulating biological functions. However, despite the involvement of miRNAs in almost all biological processes, and the importance of the hemostatic system for a multitude of actions in and beyond blood coagulation, the role o…

Abacavir Induces Arterial Thrombosis in a Murine Model.

2018

Background The purinergic system is known to underlie prothrombotic and proinflammatory vascular programs, making the profile of experimental actions demonstrated by abacavir compatible with thrombogenesis. However, direct evidence of a prothrombotic effect by the drug has been lacking. Methods The present study appraised the effects of abacavir in a well-validated animal model of arterial thrombosis. The role of ATP-P2X7 receptors in the actions of the drug was also assessed, and the actions of recognized vascular-damaging agents and other nucleoside reverse-transcriptase inhibitors (NRTIs) were evaluated and compared to those of abacavir. Results Abacavir dose-dependently promoted thrombu…

GAS6

2017

Venous thrombosis is determined by the recruitment of monocytes and neutrophils to the inflamed endothelium and is primarily influenced by the plasmatic coagulation system.1 Monocyte tissue factor (TF) was identified as the causative trigger for intraluminal fibrin formation and thrombus load in the inferior vena cava (IVC) stenosis model, resembling human deep vein thrombosis.1 Although monocyte TF is prothrombotic, the TF expressed by activated endothelial cells triggers proinflammatory protease-activated receptor signaling pathways.2,3 See accompanying article on page 1315 In the past years, GAS6 (growth arrest–specific gene-6) was described as a major regulatory protein of prothrombotic…

Paroxysmal nocturnal haemoglobinuria: When delay in diagnosis and long therapy occurs

2017

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare clonal disorder characterized by hemolytic anemia, bone marrow failure and thrombosis, caused by a somaticmutation in PIG-A gene that results in theabsence of CD55 and CD59, two important complement regulatory proteins. In thispaper, a case of PNH is retrospectively examined looking for clinical and laboratory features, and the entire course of the disease from the onset of the symptoms isdescribed, together with an adequate follow-up over a 7-years treatment period. Inthis case, the not specificity and the limited clinical relevance of the symptoms led to adelay in diagnosis. After thrombosis, Eculizumab therapy has been shown to be effec…

Tissue factor as a mediator of coagulation and signaling in cancer and chronic inflammation

2017

Thrombosis is frequently diagnosed as a first symptom in tumor patients and the clinical management of hypercoagulability in cancer patients remains challenging due to concomitant changes in risk factors for severe bleeding. It therefore remains a priority to better understand interactions of the hemostatic system with cancer biology. Specifically, further research is needed to elucidate the details and effects of new anticoagulants on extravascular coagulation and the interplay between cancer progression and chronic inflammation. In addition, it will be important to identify subgroups of cancer patients benefiting from specific modulations of the coagulation system without increasing the b…

The Commensal Microbiota Enhances ADP-Triggered Integrin αIIbβ3 Activation and von Willebrand Factor-Mediated Platelet Deposition to Type I Collagen

2020

The commensal microbiota is a recognized enhancer of arterial thrombus growth. While several studies have demonstrated the prothrombotic role of the gut microbiota, the molecular mechanisms promoting arterial thrombus growth are still under debate. Here, we demonstrate that germ-free (GF) mice, which from birth lack colonization with a gut microbiota, show diminished static deposition of washed platelets to type I collagen compared with their conventionally raised (CONV-R) counterparts. Flow cytometry experiments revealed that platelets from GF mice show diminished activation of the integrin αIIbβ3 (glycoprotein IIbIIIa) when activated by the platelet agonist adenosine diphosphate (ADP). Fu…