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Transfusion Aug 2022Tranexamic acid (TXA) is a popular antifibrinolytic drug widely used in hemorrhagic trauma patients and cardiovascular, orthopedic, and gynecological surgical patients.... (Review)
Review
Tranexamic acid (TXA) is a popular antifibrinolytic drug widely used in hemorrhagic trauma patients and cardiovascular, orthopedic, and gynecological surgical patients. TXA binds plasminogen and prevents its maturation to the fibrinolytic enzyme plasmin. A number of studies have demonstrated the broad life-saving effects of TXA in trauma, superior to those of other antifibrinolytic agents. Besides preventing fibrinolysis and blood loss, TXA has been reported to suppress posttraumatic inflammation and edema. Although the efficiency of TXA transcends simple inhibition of fibrinolysis, little is known about its mechanisms of action besides the suppression of plasmin maturation. Understanding the broader effects of TXA at the cell, organ, and organism levels are required to elucidate its potential mechanisms of action transcending antifibrinolytic activity. In this article, we provide a brief review of the current clinical use of TXA and then focus on the effects of TXA beyond antifibrinolytics such as its anti-inflammatory activity, protection of the endothelial and epithelial monolayers, stimulation of mitochondrial respiration, and suppression of melanogenesis.
Topics: Antifibrinolytic Agents; Blood Coagulation Disorders; Fibrinolysin; Fibrinolysis; Hemorrhage; Humans; Tranexamic Acid
PubMed: 35834488
DOI: 10.1111/trf.16976 -
Journal of Thrombosis and Haemostasis :... Dec 2023Fibrinolysis is the system primarily responsible for removal of fibrin deposits and blood clots in the vasculature. The terminal enzyme in the pathway, plasmin, is... (Review)
Review
Fibrinolysis is the system primarily responsible for removal of fibrin deposits and blood clots in the vasculature. The terminal enzyme in the pathway, plasmin, is formed from its circulating precursor, plasminogen. Fibrin is by far the most legendary substrate, but plasmin is notoriously prolific and is known to cleave many other proteins and participate in the activation of other proteolytic systems. Fibrinolysis is often overshadowed by the coagulation system and viewed as a simplistic poorer relation. However, the primordial plasminogen activators evolved alongside the complement system, approximately 70 million years before coagulation saw the light of day. It is highly likely that the plasminogen activation system evolved with its roots in primordial immunity. Almost all immune cells harbor at least one of a dozen plasminogen receptors that allow plasmin formation on the cell surface that in turn modulates immune cell behavior. Similarly, numerous pathogens express their own plasminogen activators or contain surface proteins that provide binding sites for host plasminogen. The fibrinolytic system has been harnessed for clinical medicine for many decades with the development of thrombolytic drugs and antifibrinolytic agents. Our refined understanding and appreciation of the fibrinolytic system and its alliance with infection and immunity and beyond are paving the way for new developments and interest in novel therapeutics and applications. One must ponder as to whether the nomenclature of the system hampered our understanding, by focusing on fibrin, rather than the complex myriad of interactions and substrates of the plasminogen activation system.
Topics: Humans; Fibrinolysis; Fibrinolysin; Plasminogen Activators; Plasminogen; Fibrin; Serine Proteases
PubMed: 38000850
DOI: 10.1016/j.jtha.2023.09.012 -
Advanced Science (Weinheim,... Aug 2023The circadian clock in animals and humans plays crucial roles in multiple physiological processes. Disruption of circadian homeostasis causes detrimental effects. Here,...
The circadian clock in animals and humans plays crucial roles in multiple physiological processes. Disruption of circadian homeostasis causes detrimental effects. Here, it is demonstrated that the disruption of the circadian rhythm by genetic deletion of mouse brain and muscle ARNT-like 1 (Bmal1) gene, coding for the key clock transcription factor, augments an exacerbated fibrotic phenotype in various tumors. Accretion of cancer-associated fibroblasts (CAFs), especially the alpha smooth muscle actin positive myoCAFs, accelerates tumor growth rates and metastatic potentials. Mechanistically, deletion of Bmal1 abrogates expression of its transcriptionally targeted plasminogen activator inhibitor-1 (PAI-1). Consequently, decreased levels of PAI-1 in the tumor microenvironment instigate plasmin activation through upregulation of tissue plasminogen activator and urokinase plasminogen activator. The activated plasmin converts latent TGF-β into its activated form, which potently induces tumor fibrosis and the transition of CAFs into myoCAFs, the latter promoting cancer metastasis. Pharmacological inhibition of the TGF-β signaling largely ablates the metastatic potentials of colorectal cancer, pancreatic ductal adenocarcinoma, and hepatocellular carcinoma. Together, these data provide novel mechanistic insights into disruption of the circadian clock in tumor growth and metastasis. It is reasonably speculated that normalization of the circadian rhythm in patients provides a novel paradigm for cancer therapy.
Topics: Mice; Humans; Animals; Transforming Growth Factor beta; Tissue Plasminogen Activator; Fibrinolysin; Plasminogen Activator Inhibitor 1; Liver Neoplasms; Muscles; Brain; Tumor Microenvironment
PubMed: 37330661
DOI: 10.1002/advs.202301505 -
Journal of Dental Research Aug 2023The hemostatic and inflammatory systems work hand in hand to maintain homeostasis at mucosal barrier sites. Among the factors of the hemostatic system, fibrin is well... (Review)
Review
The hemostatic and inflammatory systems work hand in hand to maintain homeostasis at mucosal barrier sites. Among the factors of the hemostatic system, fibrin is well recognized for its role in mucosal homeostasis, wound healing, and inflammation. Here, we present a basic overview of the fibrinolytic system, discuss fibrin as an innate immune regulator, and provide recent work uncovering the role of fibrin-neutrophil activation as a regulator of mucosal/periodontal homeostasis. We reason that the role of fibrin in periodontitis becomes most evident in individuals with the Mendelian genetic defect, congenital plasminogen (PLG) deficiency, who are predisposed to severe periodontitis in childhood due to a defect in fibrinolysis. Consistent with plasminogen deficiency being a risk factor for periodontitis, recent genomics studies uncover genetic polymorphisms in , encoding plasminogen, being significantly associated with periodontal disease, and suggesting variants as candidate risk indicators for common forms of periodontitis.
Topics: Humans; Fibrinolysis; Fibrinolysin; Plasminogen; Fibrin; Periodontitis; Hemostatics
PubMed: 37506226
DOI: 10.1177/00220345231171837 -
Archives of Oral Biology Feb 2017
Topics: Fibrinolysin; Mouth; Plasminogen; Plasminogen Activators; Plasminogen Inactivators
PubMed: 27955946
DOI: 10.1016/j.archoralbio.2016.12.004 -
Current Pharmaceutical Design 2018Vitreomacular traction occurs due to incomplete or anomalous posterior vitreous detachment. Over time, the vitreous pulls anteriorly and causes retinal distortion and... (Review)
Review
Vitreomacular traction occurs due to incomplete or anomalous posterior vitreous detachment. Over time, the vitreous pulls anteriorly and causes retinal distortion and eventually reduced vision. Traditionally, vitreomacular traction was treated with vitrectomy surgery. In the past few years, there is a paradigm shift towards pharmacologic vitreolysis, which involves the intravitreal injection of enzymatic and non-enzymatic agents that facilitate posterior vitreous detachment. Many agents have been investigated and trialled including plasmin, microplasmin (Ocriplasmin), hyaluronidase, nattokinase, chondroitinase and dispase. This review will focus on the progress and current status in this research.
Topics: Animals; Chondroitinases and Chondroitin Lyases; Endopeptidases; Fibrinolysin; Humans; Hyaluronoglucosaminidase; Intravitreal Injections; Subtilisins; Traction; Vitreous Detachment
PubMed: 30674252
DOI: 10.2174/1381612825666190124102148 -
International Journal of Laboratory... Oct 2017Fibrinolysis is an important and integral part of the hemostatic system. Acting as a balance to blood coagulation, the fibrinolytic system protects the body from... (Review)
Review
Fibrinolysis is an important and integral part of the hemostatic system. Acting as a balance to blood coagulation, the fibrinolytic system protects the body from unwanted thrombus formation and occlusion of blood vessels. As long as blood coagulation and fibrinolysis remain in equilibrium, response to injury, such as vessel damage, is appropriately regulated. However, alterations in this balance may lead to thrombosis or bleeding. A variety of methods have been proposed to assess fibrinolytic activity in blood or its components, but due to the complexity of the system, the design of a "gold standard" assay that reflects overall fibrinolysis has remained an elusive goal. In this review, we describe the most commonly used methods that have been described, such as thromboelastography (TEG and ROTEM), global fibrinolytic capacity in plasma and whole blood, plasma turbidity methods, simultaneous thrombin and plasmin generation assays, euglobulin clot lysis time and fibrin plate methods. All of these assays have strengths and limitations. We suggest that some methods may be preferable for detecting hypofibrinolytic conditions, whereas others may be better for detecting hyperfibrinolytic states.
Topics: Blood Coagulation; Blood Coagulation Tests; Fibrin Clot Lysis Time; Fibrinolysin; Fibrinolysis; Hemostasis; Humans; Reference Values; Thrombelastography; Thrombin
PubMed: 28497494
DOI: 10.1111/ijlh.12688 -
JCI Insight Apr 2023Sepsis is a lethal syndrome characterized by systemic inflammation and abnormal coagulation. Despite therapeutic advances, sepsis mortality remains substantially high....
Sepsis is a lethal syndrome characterized by systemic inflammation and abnormal coagulation. Despite therapeutic advances, sepsis mortality remains substantially high. Herein, we investigated the role of the plasminogen/plasmin (Plg/Pla) system during sepsis. Plasma levels of Plg were significantly lower in mice subjected to severe compared with nonsevere sepsis, whereas systemic levels of IL-6, a marker of sepsis severity, were higher in severe sepsis. Plg levels correlated negatively with IL-6 in both septic mice and patients, whereas plasminogen activator inhibitor-1 levels correlated positively with IL-6. Plg deficiency render mice susceptible to nonsevere sepsis induced by cecal ligation and puncture (CLP), resulting in greater numbers of neutrophils and M1 macrophages, liver fibrin(ogen) deposition, lower efferocytosis, and increased IL-6 and neutrophil extracellular trap (NET) release associated with organ damage. Conversely, inflammatory features, fibrin(ogen), and organ damage were substantially reduced, and efferocytosis was increased by exogenous Pla given during CLP- and LPS-induced endotoxemia. Plg or Pla protected mice from sepsis-induced lethality and enhanced the protective effect of antibiotics. Mechanistically, Plg/Pla-afforded protection was associated with regulation of NET release, requiring Pla-protease activity and lysine binding sites. Plg/Pla are important host-protective players during sepsis, controlling local and systemic inflammation and collateral organ damage.
Topics: Mice; Animals; Fibrinolysin; Plasminogen; Extracellular Traps; Interleukin-6; Inflammation; Sepsis; Fibrin
PubMed: 36917195
DOI: 10.1172/jci.insight.166044 -
Journal of Thrombosis and Haemostasis :... Dec 2019Fibrinolytic agents including plasmin and plasminogen activators improve outcomes in acute ischemic stroke and thrombosis by recanalizing occluded vessels. In the... (Review)
Review
Fibrinolytic agents including plasmin and plasminogen activators improve outcomes in acute ischemic stroke and thrombosis by recanalizing occluded vessels. In the decades since their introduction into clinical practice, several limitations of have been identified in terms of both efficacy and bleeding risk associated with these agents. Engineered nanoparticles and microparticles address some of these limitations by improving circulation time, reducing inhibition and degradation in circulation, accelerating recanalization, improving targeting to thrombotic occlusions, and reducing off-target effects; however, many particle-based approaches have only been used in preclinical studies to date. This review covers four advances in coupling fibrinolytic agents with engineered particles: (a) modifications of plasminogen activators with macromolecules, (b) encapsulation of plasminogen activators and plasmin in polymer and liposomal particles, (c) triggered release of encapsulated fibrinolytic agents and mechanical disruption of clots with ultrasound, and (d) enhancing targeting with magnetic particles and magnetic fields. Technical challenges for the translation of these approaches to the clinic are discussed.
Topics: Animals; Drug Carriers; Drug Compounding; Fibrinolysin; Fibrinolysis; Fibrinolytic Agents; High-Energy Shock Waves; Humans; Liposomes; Magnetite Nanoparticles; Nanomedicine; Nanoparticles; Plasminogen Activators; Thrombolytic Therapy
PubMed: 31529593
DOI: 10.1111/jth.14637 -
Journal of Tissue Engineering and... May 2022Segmental recanalization of chronically occluded arteries was observed in patients with chronic limb-threatening ischemia (CLTI) treated with Filgrastim, a granulocyte...
Segmental recanalization of chronically occluded arteries was observed in patients with chronic limb-threatening ischemia (CLTI) treated with Filgrastim, a granulocyte colony stimulating factor, every 72 h for up to a month, and an infra-geniculate programmed compression pump (PCP) for 3 h daily. Molecular evidence for fibrinolysis and neovascularization was sought. CLTI patients were treated with PCP alone (N = 19), or with Filgrastim and PCP (N = 8 and N = 6, at two institutions). Enzyme-Linked Immunosorbent Assay was used to measure the plasma concentration of plasmin and of fibrin degradation products (FDP), and the serum concentration of proteins associated with neovascularization. In the PCP-alone group, blood was sampled on Day 1 (baseline) and after 30 days of daily PCP. In the Filgrastim and PCP group, blood was drawn on Day 1, and 1 day after the 5th and the 10th Filgrastim doses. Each blood draw occurred before and after 2 h of supervised PCP. Significant (p < 0.01) PCP independent increases in the plasma concentration of plasmin (>10-fold) and FDP (>5-fold) were observed 1 day after both the 5th and the 10th Filgrastim doses, compared to Day 1. Significant (p < 0.05) increases in the concentration of pro-angiogenic proteins (e.g., HGF, MMP-9, VEGF A) were also observed. Filgrastim at this novel dosimetry induced fibrinolysis without causing acute hemorrhage, in addition to inducing a pro-angiogenic milieu conducive to NV. Further clinical testing is warranted at this novel dosimetry in CLTI, as well as in other chronically ischemic tissue beds. Trial registration. https://clinicaltrials.gov/ct2/show/NCT02802852.
Topics: Blood Group Antigens; Fibrinolysin; Fibrinolysis; Filgrastim; Granulocyte Colony-Stimulating Factor; Humans; Neovascularization, Pathologic; Recombinant Proteins
PubMed: 35175691
DOI: 10.1002/term.3284