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Foods (Basel, Switzerland) Apr 2024A novel fibrinolytic enzyme was produced by the liquid fermentation of . The enzyme was purified from the culture supernatant by hydrophobic interactions, gel...
A novel fibrinolytic enzyme was produced by the liquid fermentation of . The enzyme was purified from the culture supernatant by hydrophobic interactions, gel filtration, and ion exchange chromatographies. It was purified by 241.02-fold, with a specific activity of 3619 U/mg and a final yield of 10.02%. SDS-PAGE analysis confirmed the purity of the enzyme, showing a single band with a molecular weight of 19.5 kDa. The first nine amino acids of the N-terminal of the purified enzyme were A-T-Y-T-G-G-S-Q-T. The enzyme exhibited optimal activity at a temperature of 42 °C and pH 7.6. Its activity was significantly improved by Zn, K, Ca, Mn, and Mg while being inhibited by Fe, Fe, Al, and Ba. The activity of the enzyme was completely inhibited by ethylenediamine tetraacetic acid (EDTA), and it was also dose-dependently inhibited by phenylmethylsulfonyl fluoride (PMSF) and soy trypsin inhibitor (SBTI). However, inhibitors such as N-α-tosyl-L-phenylalanine chloromethyl ketone (TPCK), aprotinin, and pepstatin did not significantly affect its activity, suggesting that the enzyme was a serine-like metalloproteinase. The enzyme acted as both a plasmin-like fibrinolytic enzyme and a plasminogen activator, and it also exhibited the capability to hydrolyze fibrinogen and fibrin. In vitro, it demonstrated the ability to dissolve blood clots and exhibit anticoagulant properties. Furthermore, it was found that the enzyme prolonged activated partial thromboplastin time (APTT), prothrombin time (PT), and thrombin time (TT), and reduced the levels of fibrinogen (FIB) and prothrombin activity (PA). Based on these studies, the enzyme has great potential to be developed as a natural agent for the prevention and treatment of thrombotic diseases.
PubMed: 38731663
DOI: 10.3390/foods13091292 -
Minerva Medica Jun 2024Stroke confers a severe global healthcare burden, hence exploring risk factors for stroke occurrence and prognosis is important for stroke prevention and post-stroke... (Review)
Review
Stroke confers a severe global healthcare burden, hence exploring risk factors for stroke occurrence and prognosis is important for stroke prevention and post-stroke management strategies. Endogenous fibrinolysis is a spontaneous physiological protective mechanism that dissolves thrombus to maintain vascular patency. Recently, impaired endogenous fibrinolysis has been considered as a potential novel cardiovascular risk factor, but its link with ischaemic stroke in the past has been underappreciated. In this review, we summarize the latest mechanisms of endogenous fibrinolysis, review the current evidence and data on endogenous fibrinolysis in ischemic stroke. It includes the structure of thrombus in ischemic stroke patients, the effect of fibrin structure on the endogenous fibrinolytic efficiency, and the association between intravenous thrombolytic therapy and endogenous fibrinolysis in ischemic stroke. It also includes the single factors (tissue plasminogen activator, urokinase plasminogen activator, plasminogen activator inhibitor-1, thrombin activatable fibrinolysis inhibitor, complement component 3, complement component 5, alpha-2-antiplasmin, plasmin-alpha-2-antiplasmin complex, and lipoprotein[a]), and the global assessments of endogenous fibrinolysis status (thromboelastography, rotational thromboelastometry, and global thrombosis test), and their potential as predictors to identify occurrence or unfavorable functional outcomes of ischemic stroke. All of these assessments present advantages and limitations, and we suggest that the global thrombosis test may be more appropriate for detecting impaired endogenous fibrinolysis status in ischemic stroke patients.
Topics: Humans; Fibrinolysis; Ischemic Stroke; Prognosis; Thrombolytic Therapy; Thrombosis
PubMed: 38727704
DOI: 10.23736/S0026-4806.24.09133-X -
Frontiers in Immunology 2024Relapsing fever (RF) remains a neglected human disease that is caused by a number of diverse pathogenic () species. Characterized by high cell densities in human blood,...
INTRODUCTION
Relapsing fever (RF) remains a neglected human disease that is caused by a number of diverse pathogenic () species. Characterized by high cell densities in human blood, relapsing fever spirochetes have developed plentiful strategies to avoid recognition by the host defense mechanisms. In this scenario, spirochetal lipoproteins exhibiting multifunctional binding properties in the interaction with host-derived molecules are known to play a key role in adhesion, fibrinolysis and complement activation.
METHODS
Binding of CihC/FbpC orthologs to different human proteins and conversion of protein-bound plasminogen to proteolytic active plasmin were examined by ELISA. To analyze the inhibitory capacity of CihC/FbpC orthologs on complement activation, a microtiter-based approach was performed. Finally, AlphaFold predictions were utilized to identified the complement-interacting residues.
RESULTS AND DISCUSSION
Here, we elucidate the binding properties of CihC/FbpC-orthologs from distinct RF spirochetes including , , , and to human fibronectin, plasminogen, and complement component C1r. All CihC/FbpC-orthologs displayed similar binding properties to fibronectin, plasminogen, and C1r, respectively. Functional studies revealed a dose dependent binding of plasminogen to all borrelial proteins and conversion to active plasmin. The proteolytic activity of plasmin was almost completely abrogated by tranexamic acid, indicating that lysine residues are involved in the interaction with this serine protease. In addition, a strong inactivation capacity toward the classical pathway could be demonstrated for the wild-type CihC/FbpC-orthologs as well as for the C-terminal CihC fragment of . Pre-incubation of human serum with borrelial molecules except CihC/FbpC variants lacking the C-terminal region protected serum-susceptible cells from complement-mediated lysis. Utilizing AlphaFold2 predictions and existing crystal structures, we mapped the putative key residues involved in C1r binding on the CihC/FbpC orthologs attempting to explain the relatively small differences in C1r binding affinity despite the substitutions of key residues. Collectively, our data advance the understanding of the multiple binding properties of structural and functional highly similar molecules of relapsing fever spirochetes proposed to be involved in pathogenesis and virulence.
Topics: Humans; Bacterial Adhesion; Bacterial Proteins; Borrelia; Complement Activation; Complement System Proteins; Fibrinolysin; Fibrinolysis; Fibronectins; Host-Pathogen Interactions; Immune Evasion; Plasminogen; Protein Binding; Relapsing Fever
PubMed: 38726006
DOI: 10.3389/fimmu.2024.1390468 -
Current Opinion in Hematology May 2024Von Willebrand factor (VWF) plays a pivotal role in primary hemostasis. A Disintegrin And Metalloproteinase with a ThromboSpondin type 1 motif, member 13 (ADAMTS13) is...
PURPOSE OF REVIEW
Von Willebrand factor (VWF) plays a pivotal role in primary hemostasis. A Disintegrin And Metalloproteinase with a ThromboSpondin type 1 motif, member 13 (ADAMTS13) is primarily responsible for cleaving ultra-large VWF multimers into smaller, less adhesive forms. However, plasmin has also been shown to cleave VWF multimers. This proteolytic cleavage of VWF results in a decreased multimer size and, hence, a lower VWF activity. This review aims to present a comprehensive overview of the involvement of plasmin-mediated VWF proteolysis in (micro)thrombosis.
RECENT FINDINGS
Plasmin-mediated VWF proteolysis has been suggested to play a role in various pathologies involving microthrombosis in combination with an imbalance in VWF antigen levels and ADAMTS13 activity, as well as activation of the fibrinolytic system, but quantitative assays to demonstrate this were lacking. Recently, a VHH-based bioassay was developed designed specifically to quantify plasmin-cleaved VWF (cVWF). The novel ELISA assay holds significant promise for gaining further insights into the clinical relevance of plasmin-mediated VWF proteolysis in several pathologies. Furthermore, local plasmin activation at the site of microthrombosis has been shown to be a promising treatment strategy by degrading VWF-rich microthrombi.
SUMMARY
Plasmin-mediated proteolysis of VWF is observed during microthrombosis; however, it remains unclear whether it impacts disease severity. A novel ELISA method to detect cVWF will improve our understanding of the clinical role of plasmin-mediated VWF degradation.
PubMed: 38723202
DOI: 10.1097/MOH.0000000000000825 -
PloS One 2024The risk of major bleeding complications in catheter directed thrombolysis (CDT) for acute limb ischemia (ALI) remains high, with reported major bleeding complication...
INTRODUCTION
The risk of major bleeding complications in catheter directed thrombolysis (CDT) for acute limb ischemia (ALI) remains high, with reported major bleeding complication rates in up to 1 in every 10 treated patients. Fibrinogen was the only predictive marker used for bleeding complications in CDT, despite the lack of high quality evidence to support this. Therefore, recent international guidelines recommend against the use of fibrinogen during CDT. However, no alternative biomarkers exist to effectively predict CDT-related bleeding complications. The aim of the POCHET biobank is to prospectively assess the rate and etiology of bleeding complications during CDT and to provide a biobank of blood samples to investigate potential novel biomarkers to predict bleeding complications during CDT.
METHODS
The POCHET biobank is a multicentre prospective biobank. After informed consent, all consecutive patients with lower extremity ALI eligible for CDT are included. All patients are treated according to a predefined standard operating procedure which is aligned in all participating centres. Baseline and follow-up data are collected. Prior to CDT and subsequently every six hours, venous blood samples are obtained and stored in the biobank for future analyses. The primary outcome is the occurrence of non-access related major bleeding complications, which is assessed by an independent adjudication committee. Secondary outcomes are non-major bleeding complications and other CDT related complications. Proposed biomarkers to be investigated include fibrinogen, to end the debate on its usefulness, anti-plasmin and D-Dimer.
DISCUSSION AND CONCLUSION
The POCHET biobank provides contemporary data and outcomes of patients during CDT for ALI, coupled with their blood samples taken prior and during CDT. Thereby, the POCHET biobank is a real world monitor on biomarkers during CDT, supporting a broad spectrum of future research for the identification of patients at high risk for bleeding complications during CDT and to identify new biomarkers to enhance safety in CDT treatment.
Topics: Humans; Hemorrhage; Thrombolytic Therapy; Prospective Studies; Biomarkers; Male; Female; Fibrinogen; Peripheral Arterial Disease; Aged; Arterial Occlusive Diseases; Middle Aged
PubMed: 38722842
DOI: 10.1371/journal.pone.0302830 -
BMC Biotechnology May 2024Venous thromboembolism (VTE), is a noteworthy complication in individuals with gastric cancer, but the current diagnosis and treatment methods lack accuracy. In this...
BACKGROUND
Venous thromboembolism (VTE), is a noteworthy complication in individuals with gastric cancer, but the current diagnosis and treatment methods lack accuracy. In this study, we developed a t-PAIC chemiluminescence kit and employed chemiluminescence to detect the tissue plasminogen activator inhibitor complex (t-PAIC), thrombin-antithrombin III complex (TAT), plasmin-α2-plasmin inhibitor complex (PIC) and thrombomodulin (TM), combined with D-dimer and fibrin degradation products (FDP), to investigate their diagnostic potential for venous thrombosis in gastric cancer patients. The study assessed variations in six indicators among gastric cancer patients at different stages.
RESULTS
The t-PAIC reagent showed LOD is 1.2 ng/mL and a linear factor R greater than 0.99. The reagents demonstrated accurate results, with all accuracy deviations being within 5%. The intra-batch and inter-batch CVs for the t-PAIC reagent were both within 8%. The correlation coefficient R between this method and Sysmex was 0.979. Gastric cancer patients exhibited elevated levels of TAT, PIC, TM, D-D, FDP compared to the healthy population, while no significant difference was observed in t-PAIC. In the staging of gastric cancer, patients in III-IV stages exhibit higher levels of the six markers compared to those in I-II stages. The ROC curve indicates an enhancement in sensitivity and specificity of the combined diagnosis of four or six indicators.
CONCLUSION
Our chemiluminescence assay performs comparably to Sysmex's method and at a reduced cost. The use of multiple markers, including t-PAIC, TM, TAT, PIC, D-D, and FDP, is superior to the use of single markers for diagnosing VTE in patients with malignant tumors. Gastric cancer patients should be screened for the six markers to facilitate proactive prophylaxis, determine the most appropriate treatment timing, ameliorate their prognosis, decrease the occurrence of venous thrombosis and mortality, and extend their survival.
Topics: Humans; Stomach Neoplasms; Male; Middle Aged; Luminescent Measurements; Female; Aged; Antithrombin III; Thrombomodulin; Fibrin Fibrinogen Degradation Products; alpha-2-Antiplasmin; Adult; Fibrinolysin; Venous Thromboembolism; Peptide Hydrolases
PubMed: 38720310
DOI: 10.1186/s12896-024-00850-9 -
Nature May 2024Lipoprotein(a) (Lp(a)), an independent, causal cardiovascular risk factor, is a lipoprotein particle that is formed by the interaction of a low-density lipoprotein (LDL)...
Lipoprotein(a) (Lp(a)), an independent, causal cardiovascular risk factor, is a lipoprotein particle that is formed by the interaction of a low-density lipoprotein (LDL) particle and apolipoprotein(a) (apo(a)). Apo(a) first binds to lysine residues of apolipoprotein B-100 (apoB-100) on LDL through the Kringle IV (K) 7 and 8 domains, before a disulfide bond forms between apo(a) and apoB-100 to create Lp(a) (refs. ). Here we show that the first step of Lp(a) formation can be inhibited through small-molecule interactions with apo(a) K7-8. We identify compounds that bind to apo(a) K7-8, and, through chemical optimization and further application of multivalency, we create compounds with subnanomolar potency that inhibit the formation of Lp(a). Oral doses of prototype compounds and a potent, multivalent disruptor, LY3473329 (muvalaplin), reduced the levels of Lp(a) in transgenic mice and in cynomolgus monkeys. Although multivalent molecules bind to the Kringle domains of rat plasminogen and reduce plasmin activity, species-selective differences in plasminogen sequences suggest that inhibitor molecules will reduce the levels of Lp(a), but not those of plasminogen, in humans. These data support the clinical development of LY3473329-which is already in phase 2 studies-as a potent and specific orally administered agent for reducing the levels of Lp(a).
Topics: Animals; Female; Humans; Male; Mice; Administration, Oral; Drug Discovery; Kringles; Lipoprotein(a); Macaca fascicularis; Mice, Transgenic; Small Molecule Libraries; Plasminogen; Species Specificity; Clinical Trials, Phase II as Topic; Apolipoproteins A
PubMed: 38720069
DOI: 10.1038/s41586-024-07387-z -
Hormone Molecular Biology and Clinical... Jun 2024D-dimer, a universally unique marker for fibrin degradation, is generated through the enzymatic interplay of thrombin, factor XIIIa, and plasmin. The emergence of... (Review)
Review
D-dimer, a universally unique marker for fibrin degradation, is generated through the enzymatic interplay of thrombin, factor XIIIa, and plasmin. The emergence of D-dimer-containing fibrin molecules occurs in both intravascular and extravascular spaces during pivotal physiological processes like haemostasis, thrombosis, and tissue repair. Given the inherently physiological nature of fibrin formation and fibrinolysis, basal levels of D-dimer fragments are present in plasma. Beyond its role as a marker of routine physiological processes, aberrations in D-dimer levels are indicative of a spectrum of conditions, both non-pathological and pathological. The clinical utility of D-dimer has been firmly established, particularly in scenarios like venous thromboembolism (VTE), pulmonary embolism (PE), deep vein thrombosis (DVT), and disseminated intravascular coagulation (DIC). Additionally, recent applications have extended to assess the prognosis of COVID-19. While D-dimer is commonly associated with thrombotic conditions, its elevation is not confined to these conditions alone. Elevated D-dimer levels are observed across various diseases, where its significance extends beyond diagnostic indicators to prognostic implications.
Topics: Humans; Fibrin Fibrinogen Degradation Products; COVID-19; Biomarkers; SARS-CoV-2; Disseminated Intravascular Coagulation; Fibrinolysis; Venous Thromboembolism; Prognosis; Pulmonary Embolism; Venous Thrombosis
PubMed: 38716869
DOI: 10.1515/hmbci-2022-0093 -
World Journal of Orthopedics Apr 2024Tranexamic acid (TXA), a synthetic antifibrinolytic drug, effectively reduces blood loss by inhibiting plasmin-induced fibrin breakdown. This is the first study in the...
BACKGROUND
Tranexamic acid (TXA), a synthetic antifibrinolytic drug, effectively reduces blood loss by inhibiting plasmin-induced fibrin breakdown. This is the first study in the United Kingdom to investigate the effectiveness of TXA in the surgical management of isolated spine trauma.
AIM
To assess the safety of TXA in isolated spine trauma. The primary and secondary outcomes are to assess the rate of thromboembolic events and to evaluate blood loss and the incidence of blood transfusion, respectively.
METHODS
This prospective observational study included patients aged ≥ 17 years with isolated spine trauma requiring surgical intervention over a 6-month period at two major trauma centers in the United Kingdom.
RESULTS
We identified 67 patients: 26 (39%) and 41 (61%) received and did not receive TXA, respectively. Both groups were matched in terms of age, gender, American Society of Anesthesiologists grade, and mechanism of injury. A higher proportion of patients who received TXA had a subaxial cervical spine injury classification or thoracolumbar injury classification score > 4 (74% 56%). All patients in the TXA group underwent an open approach with a mean of 5 spinal levels involved and an average operative time of 203 min, compared with 24 patients (58%) in the non-TXA group who underwent an open approach with an average of 3 spinal levels involved and a mean operative time of 159 min. Among patients who received TXA, blood loss was < 150 and 150-300 mL in 8 (31%) and 15 (58%) patients, respectively. There were no cases of thromboembolic events in any patient who received TXA.
CONCLUSION
Our study demonstrated that TXA is safe for isolated spine trauma. It is challenging to determine whether TXA effectively reduces blood loss because most surgeons prefer TXA for open or multilevel cases. Further, larger studies are necessary to explore the rate, dosage, and mode of administration of TXA.
PubMed: 38680673
DOI: 10.5312/wjo.v15.i4.346