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Shock (Augusta, Ga.) Mar 2016Sepsis affects practically all aspects of endothelial cell (EC) function and is thought to be the key factor in the progression from sepsis to organ failure. Endothelial... (Review)
Review
Sepsis affects practically all aspects of endothelial cell (EC) function and is thought to be the key factor in the progression from sepsis to organ failure. Endothelial functions affected by sepsis include vasoregulation, barrier function, inflammation, and hemostasis. These are among other mechanisms often mediated by glycocalyx shedding, such as abnormal nitric oxide metabolism, up-regulation of reactive oxygen species generation due to down-regulation of endothelial-associated antioxidant defenses, transcellular communication, proteases, exposure of adhesion molecules, and activation of tissue factor. This review covers current insight in EC-associated hemostatic responses to sepsis and the EC response to inflammation. The endothelial cell lining is highly heterogeneous between different organ systems and consequently also in its response to sepsis. In this context, we discuss the response of the endothelial cell lining to sepsis in the kidney, liver, and lung. Finally, we discuss evidence as to whether the EC response to sepsis is adaptive or maladaptive. This study is a result of an Acute Dialysis Quality Initiative XIV Sepsis Workgroup meeting held in Bogota, Columbia, between October 12 and 15, 2014.
Topics: Animals; Down-Regulation; Endothelial Cells; Endothelium; Glycocalyx; Hemostasis; Humans; Nitric Oxide; Organ Specificity; Sepsis; Thromboplastin; Up-Regulation
PubMed: 26871664
DOI: 10.1097/SHK.0000000000000473 -
Critical Reviews in Biochemistry and... 2015The plasma coagulation system in mammalian blood consists of a cascade of enzyme activation events in which serine proteases activate the proteins (proenzymes and... (Review)
Review
The plasma coagulation system in mammalian blood consists of a cascade of enzyme activation events in which serine proteases activate the proteins (proenzymes and procofactors) in the next step of the cascade via limited proteolysis. The ultimate outcome is the polymerization of fibrin and the activation of platelets, leading to a blood clot. This process is protective, as it prevents excessive blood loss following injury (normal hemostasis). Unfortunately, the blood clotting system can also lead to unwanted blood clots inside blood vessels (pathologic thrombosis), which is a leading cause of disability and death in the developed world. There are two main mechanisms for triggering the blood clotting, termed the tissue factor pathway and the contact pathway. Only one of these pathways (the tissue factor pathway) functions in normal hemostasis. Both pathways, however, are thought to contribute to thrombosis. An emerging concept is that the contact pathway functions in host pathogen defenses. This review focuses on how the initiation phase of the blood clotting cascade is regulated in both pathways, with a discussion of the contributions of these pathways to hemostasis versus thrombosis.
Topics: Animals; Blood Coagulation; Hemostasis; Humans; Models, Biological; Platelet Activation; Proteolysis; Thromboplastin; Thrombosis
PubMed: 26018600
DOI: 10.3109/10409238.2015.1050550 -
ESMO Open Oct 2022Despite screening programs for early detection and the approval of human papillomavirus vaccines, around 6% of women with cervical cancer (CC) are discovered with... (Review)
Review
Despite screening programs for early detection and the approval of human papillomavirus vaccines, around 6% of women with cervical cancer (CC) are discovered with primary metastatic disease. Moreover, one-third of the patients receiving chemoradiation followed by brachytherapy for locally advanced disease will have a recurrence. At the end, the vast majority of recurrent or metastatic CC not amenable to locoregional treatments are considered incurable disease with very poor prognosis. Historically, cisplatin monotherapy, then a combination of cisplatin and paclitaxel were considered the standard of care. Ten years ago, the addition of bevacizumab to chemotherapy demonstrated favorable data in terms of response rate and overall survival. Even with this improvement, novel therapies are needed for the treatment of recurrent CC in first as well as later lines. In the last decades, a better understanding of the interactions between human papillomavirus infection and the host immune system response has focused interest on the use of immunotherapeutic drugs in CC patients. Indeed, immune checkpoint inhibitors (pembrolizumab, cemiplimab, and others) have recently emerged as novel therapeutic pillars that could provide durable responses with impact on overall survival in patients in the primary (in addition to chemotherapy) or recurrent (monotherapy) settings. Tisotumab vedotin, an antibody-drug conjugate targeting the tissue factor, is another emerging drug. Several trials in monotherapy or in combination with immunotherapy, chemotherapy, or bevacizumab showed very promising results. There is a high need for more potent biomarkers to better accurately determine which patients would receive the greatest benefit from all these aforementioned drugs, but also to identify patients with specific molecular characteristics that could benefit from other targeted therapies. The Cancer Genome Atlas Research Network identified several genes significantly mutated, potentially targetable. These molecular data have highlighted the molecular heterogeneity of CC.
Topics: Humans; Female; Uterine Cervical Neoplasms; Bevacizumab; Cisplatin; Immune Checkpoint Inhibitors; Thromboplastin; Neoplasm Recurrence, Local; Paclitaxel; Biomarkers; Papillomavirus Vaccines; Immunoconjugates
PubMed: 36108558
DOI: 10.1016/j.esmoop.2022.100579 -
Annals of the Rheumatic Diseases Feb 2019The release of neutrophil extracellular traps (NETs) represents a novel neutrophil effector function in systemic lupus erythematosus (SLE) pathogenesis. However, the...
REDD1/autophagy pathway promotes thromboinflammation and fibrosis in human systemic lupus erythematosus (SLE) through NETs decorated with tissue factor (TF) and interleukin-17A (IL-17A).
OBJECTIVES
The release of neutrophil extracellular traps (NETs) represents a novel neutrophil effector function in systemic lupus erythematosus (SLE) pathogenesis. However, the molecular mechanism underlying NET release and how NETs mediate end-organ injury in SLE remain elusive.
METHODS
NET formation and NET-related proteins were assessed in the peripheral blood and biopsies from discoid lupus and proliferative nephritis, using immunofluorescence, immunoblotting, quantitative PCR and ELISA. Autophagy was assessed by immunofluorescence and immunoblotting. The functional effects of NETs in vitro were assessed in a primary fibroblast culture.
RESULTS
Neutrophils from patients with active SLE exhibited increased basal autophagy levels leading to enhanced NET release, which was inhibited in vitro by hydroxychloroquine. NETosis in SLE neutrophils correlated with increased expression of the stress-response protein REDD1. Endothelin-1 (ET-1) and hypoxia-inducible factor-1α (HIF-1α) were key mediators of REDD1-driven NETs as demonstrated by their inhibition with bosentan and L-ascorbic acid, respectively. SLE NETs were decorated with tissue factor (TF) and interleukin-17A (IL-17A), which promoted thrombin generation and the fibrotic potential of cultured skin fibroblasts. Notably, TF-bearing and IL-17A-bearing NETs were abundant in discoid skin lesions and in the glomerular and tubulointerstitial compartment of proliferative nephritis biopsy specimens.
CONCLUSIONS
Our data suggest the involvement of REDD1/autophagy/NET axis in end-organ injury and fibrosis in SLE, a likely candidate for repositioning of existing drugs for SLE therapy. Autophagy-mediated release of TF-bearing and IL-17A-bearing NETs provides a link between thromboinflammation and fibrosis in SLE and may account for the salutary effects of hydroxychloroquine.
Topics: Autophagy; Cell Culture Techniques; Extracellular Traps; Fibroblasts; Fibrosis; Humans; Inflammation; Interleukin-17; Lupus Erythematosus, Systemic; Signal Transduction; Thromboplastin; Thrombosis; Transcription Factors
PubMed: 30563869
DOI: 10.1136/annrheumdis-2018-213181 -
Frontiers in Bioscience (Landmark... Jan 2018The abundance of evidence suggest that inflammation of immune and non-immune cells may lead to an imbalance of the pro- and anti-coagulant state during viral infections.... (Review)
Review
The abundance of evidence suggest that inflammation of immune and non-immune cells may lead to an imbalance of the pro- and anti-coagulant state during viral infections. During systemic infections, the endothelium plays a critical role in regulating hemostasis, and severe imbalances of endothelial function and activation can contribute to organ failure. Viral infections may elevate plasma levels of procoagulant markers such as TAT and D-dimer TF-positive MPs as well as von Willebrand factor (vWF). Although multiple clinical studies are showing the association of viral infection and increased prothrombotic risk, the pathological mechanisms have not been fully identified for most viral infections. Viral infection mediated TLRs activation is both cell type- and species-specific and explains the difficulties in correlating murine model data with the human data. In this review, we briefly discuss the TF-dependent coagulation activation, Toll-like receptors (TLRs) signaling during viral infections, and their contributions to the procoagulant response.
Topics: Animals; Biomarkers; Blood Coagulation; Blood Coagulation Factors; Hemostasis; Humans; Thromboplastin; Toll-Like Receptors; Virus Diseases; von Willebrand Factor
PubMed: 28930589
DOI: 10.2741/4633 -
Journal of Thrombosis and Haemostasis :... Jun 2022Tissue factor pathway inhibitor (TFPI) is an alternatively spliced anticoagulant protein that primarily dampens the initiation phase of coagulation before thrombin is... (Review)
Review
Tissue factor pathway inhibitor (TFPI) is an alternatively spliced anticoagulant protein that primarily dampens the initiation phase of coagulation before thrombin is generated. As such, TFPI's actions are localized to cells expressing TF and to sites of injury, where it is an important regulator of bleeding in hemophilia. The major splice isoforms TFPIα and TFPIβ localize to different sites within and surrounding the vasculature. Both forms directly inhibit factor Xa (FXa) via their Kunitz 2 domain and inhibit TF-FVIIa via their Kunitz 1 domain in a tight complex primarily localized to cells. By forming complexes localized to distinct cellular microenvironments and engaging additional cell surface receptors, TFPI alters cellular trafficking and signaling pathways driven by coagulation proteases of the TF pathway. TFPIα, which circulates in complex with FV and protein S, also serves an inhibitor of FXa independent of the TF initiation complex and prevents the formation of an active prothrombinase. This regulation of thrombin generation in the context of vessel injury is effectively blocked by antibodies to Kunitz 2 domain of TFPI and exploited as a therapy to restore efficient hemostasis in hemophilia.
Topics: Blood Coagulation; Factor Xa; Hemophilia A; Humans; Lipoproteins; Thrombin; Thromboplastin
PubMed: 35279938
DOI: 10.1111/jth.15697 -
Blood Jun 2022
Topics: Cryoelectron Microscopy; Factor V; Factor X; Factor Xa; Prothrombin; Thrombin; Thromboplastin
PubMed: 35708725
DOI: 10.1182/blood.2022016537 -
Journal of Thrombosis and Haemostasis :... Jul 2023The cell-based model of coagulation remains the basis of our current understanding of clinical hemostasis and thrombosis. Its advancement on the coagulation cascade... (Review)
Review
The cell-based model of coagulation remains the basis of our current understanding of clinical hemostasis and thrombosis. Its advancement on the coagulation cascade model has enabled new prohemostatic and anticoagulant treatments to be developed. In the past decade, there has been increasing evidence of the procoagulant properties of extracellular, cell-free histones (CFHs). Although high levels of circulating CFHs released following extensive cell death in acute critical illnesses, such as sepsis and trauma, have been associated with adverse coagulation outcomes, including disseminated intravascular coagulation, new information has also emerged on how its local effects contribute to physiological clot formation. CFHs initiate coagulation by tissue factor exposure, either by destruction of the endovascular barrier or induction of endoluminal tissue factor expression on endothelia and monocytes. CFHs can also bind prothrombin directly, generating thrombin via the alternative prothrombinase pathway. In amplifying and augmenting the procoagulant signal, CFHs activate and aggregate platelets, increase procoagulant material bioavailability through platelet degranulation and Weibel-Palade body exocytosis, activate intrinsic coagulation via platelet polyphosphate release, and induce phosphatidylserine exposure. CFHs also inhibit protein C activation and downregulate thrombomodulin expression to reduce anti-inflammatory and anticoagulant effects. In consolidating clot formation, CFHs augment the fibrin polymer to confer fibrinolytic resistance and integrate neutrophil extracellular traps into the clot structure. Such new information holds the promise of new therapeutic developments, including improved targeting of immunothrombotic pathologies in acute critical illnesses.
Topics: Humans; Histones; Thromboplastin; Critical Illness; Blood Coagulation; Thrombosis; Anticoagulants
PubMed: 37116754
DOI: 10.1016/j.jtha.2023.04.018 -
Thrombosis Research Dec 2022Evidence of micro- and macro-thrombi in the arteries and veins of critically ill COVID-19 patients and in autopsies highlight the occurrence of COVID-19-associated... (Review)
Review
Evidence of micro- and macro-thrombi in the arteries and veins of critically ill COVID-19 patients and in autopsies highlight the occurrence of COVID-19-associated coagulopathy (CAC). Clinical findings of critically ill COVID-19 patients point to various mechanisms for CAC; however, the definitive underlying cause is unclear. Multiple factors may contribute to the prothrombotic state in patients with COVID-19. Aberrant expression of tissue factor (TF), an initiator of the extrinsic coagulation pathway, leads to thrombotic complications during injury, inflammation, and infections. Clinical evidence suggests that TF-dependent coagulation activation likely plays a role in CAC. Multiple factors could trigger abnormal TF expression and coagulation activation in patients with severe COVID-19 infection. Proinflammatory cytokines that are highly elevated in COVID-19 (IL-1β, IL-6 and TNF-α) are known induce TF expression on leukocytes (e.g. monocytes, macrophages) and non-immune cells (e.g. endothelium, epithelium) in other conditions. Antiphospholipid antibodies, TF-positive extracellular vesicles, pattern recognition receptor (PRR) pathways and complement activation are all candidate factors that could trigger TF-dependent procoagulant activity. In addition, coagulation factors, such as thrombin, may further potentiate the induction of TF via protease-activated receptors on cells. In this systematic review, with other viral infections, we discuss potential mechanisms and cell-type-specific expressions of TF during SARS-CoV-2 infection and its role in the development of CAC.
Topics: Humans; Thromboplastin; COVID-19; Critical Illness; SARS-CoV-2; Blood Coagulation Disorders; Thrombosis
PubMed: 36265412
DOI: 10.1016/j.thromres.2022.09.025 -
Journal of Atherosclerosis and... 2016Microparticles (MPs) are small membrane vesicles that are released from many different cell types by exocytotic budding of the plasma membrane in response to cellular... (Review)
Review
Microparticles (MPs) are small membrane vesicles that are released from many different cell types by exocytotic budding of the plasma membrane in response to cellular activation or apoptosis. MPs may be involved in both physiological processes and clinical treatments because they express phospholipids, which function as procoagulants. Elevated levels of platelet-derived MPs, endothelial cell-derived MPs, and monocyte-derived MPs are observed in almost all thrombotic diseases occurring in venous and arterial beds. Several studies have shown that the quantity, cellular origin, and composition of circulating MPs depend on the type of disease, the disease state, and medical treatment. Although MPs were initially thought to be small particles with only procoagulant activity, they are now known to have many different functions. An increasing number of studies have identified new implications of elevated MPs in clinical disorders. On the basis of evidence available till date, the present review suggests that MPs may be a useful biomarker in identifying atherothrombosis.
Topics: Animals; Apoptosis; Biomarkers; Blood Platelets; Cardiovascular Diseases; Cell Membrane; Cell-Derived Microparticles; Coagulants; Diabetes Mellitus, Type 2; Endothelial Cells; Enzyme-Linked Immunosorbent Assay; Flow Cytometry; Humans; Oxidative Stress; Phospholipids; Shear Strength; Stress, Mechanical; Thromboplastin; Thrombosis
PubMed: 26412494
DOI: 10.5551/jat.32326