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Developments in Ophthalmology 2017Vitreomacular traction (VMT) is one of many possible factors involved in the etiology of diabetic macular edema (DME). Pharmacologic vitreoretinal separation is a... (Review)
Review
Vitreomacular traction (VMT) is one of many possible factors involved in the etiology of diabetic macular edema (DME). Pharmacologic vitreoretinal separation is a potential alternative to vitrectomy for VMT in diabetic retinopathy. Small case series have been published on the use of enzymatic vitreolysis in tractional DME, and demonstrate that the enzymatic release of the posterior vitreous cortex is more likely following the injection of plasmin enzyme. Further prospective and randomized clinical trials are necessary to evaluate the clinical relevance of ocriplasmin for vitreomacular traction in diabetic retinopathy, and additional studies are needed to determine more accurately which patients might benefit most from this treatment and how often and at what concentration ocriplasmin should be administered.
Topics: Diabetic Retinopathy; Fibrinolysin; Humans; Intravitreal Injections; Tomography, Optical Coherence; Visual Acuity; Vitreous Body; Vitreous Detachment
PubMed: 28427074
DOI: 10.1159/000460275 -
International Journal of Molecular... May 2023Hemostasis is a delicate balance between coagulation and fibrinolysis that regulates the formation and removal of fibrin, respectively. Positive and negative feedback...
Hemostasis is a delicate balance between coagulation and fibrinolysis that regulates the formation and removal of fibrin, respectively. Positive and negative feedback loops and crosstalk between coagulation and fibrinolytic serine proteases maintain the hemostatic balance to prevent both excessive bleeding and thrombosis. Here, we identify a novel role for the glycosylphosphatidylinositol (GPI)-anchored serine protease testisin in the regulation of pericellular hemostasis. Using in vitro cell-based fibrin generation assays, we found that the expression of catalytically active testisin on the cell surface accelerates thrombin-dependent fibrin polymerization, and intriguingly, that it subsequently promotes accelerated fibrinolysis. We find that the testisin-dependent fibrin formation is inhibited by rivaroxaban, a specific inhibitor of the central prothrombin-activating serine protease factor Xa (FXa), demonstrating that cell-surface testisin acts upstream of factor X (FX) to promote fibrin formation at the cell surface. Unexpectedly, testisin was also found to accelerate fibrinolysis by stimulating the plasmin-dependent degradation of fibrin and enhancing plasmin-dependent cell invasion through polymerized fibrin. Testisin was not a direct activator of plasminogen, but it is able to induce zymogen cleavage and the activation of pro-urokinase plasminogen activator (pro-uPA), which converts plasminogen to plasmin. These data identify a new proteolytic component that can regulate pericellular hemostatic cascades at the cell surface, which has implications for angiogenesis, cancer biology, and male fertility.
Topics: Male; Humans; Fibrinolysis; Fibrinolysin; Glycosylphosphatidylinositols; Serine Proteases; Serine Endopeptidases; Plasminogen; Urokinase-Type Plasminogen Activator; Fibrin; Hemostatics
PubMed: 37298257
DOI: 10.3390/ijms24119306 -
International Journal of Molecular... Sep 2022Nephritis-associated plasmin receptor (NAPlr) was originally isolated from the cytoplasmic fraction of group A , and was found to be the same molecule as streptococcal... (Review)
Review
Nephritis-Associated Plasmin Receptor (NAPlr): An Essential Inducer of C3-Dominant Glomerular Injury and a Potential Key Diagnostic Biomarker of Infection-Related Glomerulonephritis (IRGN).
Nephritis-associated plasmin receptor (NAPlr) was originally isolated from the cytoplasmic fraction of group A , and was found to be the same molecule as streptococcal glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and plasmin receptor (Plr) on the basis of nucleotide and amino acid sequence homology. Its main functions include GAPDH activity, plasmin-binding capacity, and direct activation of the complement alternative pathway (A-P). Plasmin trapped by deposited NAPlr triggers the degradation of extracellular matrix proteins, such as glomerular basement membranes and mesangial matrix, and the accumulation of macrophages and neutrophils, leading to the induction of plasmin-related endocapillary glomerular inflammation. Deposited NAPlr at glomerular endocapillary site directly activates the complement A-P, and the endocapillary release of complement-related anaphylatoxins, C3a and C5a, amplify the in situ endocapillary glomerular inflammation. Subsequently, circulating and in situ-formed immune complexes participate in the glomerular injury resulting in NAPlr-mediated glomerulonephritis. The disease framework of infection-related glomerulonephritis (IRGN) has been further expanded. GAPDH of various bacteria other than have been found to react with anti-NAPlr antibodies and to possess plasmin-binding activities, allowing glomerular NAPlr and plasmin activity to be utilized as key biomarkers of IRGN.
Topics: Biomarkers; Fibrinolysin; Glomerulonephritis; Glyceraldehyde-3-Phosphate Dehydrogenases; Humans; Inflammation; Nephritis; Receptors, Peptide; Streptococcal Infections
PubMed: 36077377
DOI: 10.3390/ijms23179974 -
Expert Opinion on Drug Safety Sep 2016Pharmacologic vitreolysis is a strategy used to treat anomalous posterior vitreous detachment, by weakening vitreoretinal adhesion with an intravitreal drug.... (Review)
Review
INTRODUCTION
Pharmacologic vitreolysis is a strategy used to treat anomalous posterior vitreous detachment, by weakening vitreoretinal adhesion with an intravitreal drug. Pharmacologic vitreolysis facilitates surgery, and abnormalities of the vitreoretinal interface including vitreomacular traction (VMT) and early stage macular hole (MH) could be resolved. Ocriplasmin is a recombinant protease, active against fibronectin and laminin, which are important components of the vitreoretinal interface. Ocriplasmin has been approved for symptomatic treatment of VMT and MH with visible traction, and it functions by dissolving the proteins that link the vitreous to the macula, thereby creating a complete posterior vitreous detachment (PVD).
AREAS COVERED
This paper reviews the current knowledge and status of investigations regarding the use of ocriplasmin for pharmacologic vitreolysis and its safety.
EXPERT OPINION
Ocriplasmin is a non-specific enzyme; therefore, it dissolves vitreal proteins as well as possibly proteins associated with visual function in the retina, choroid, and lens. Ocular adverse events (OAEs) of ocriplasmin include transient visual loss, intraocular inflammation, vitreous floaters, lens opacification, zonular instability of the lens, and intraocular hemorrhage. The prevalence of the OAEs is very low; however, on rare occasions, they can result in widespread retinal dysfunction. Research into the acute and long-term safety of ocriplasmin is required.
Topics: Animals; Fibrinolysin; Humans; Intravitreal Injections; Peptide Fragments; Retina; Retinal Perforations; Tissue Adhesions; Treatment Outcome; Vitreous Body; Vitreous Detachment
PubMed: 27388220
DOI: 10.1080/14740338.2016.1208169 -
Molecular and Cellular Biochemistry Aug 2018Plasmin is a fibrinolytic factor and a serine protease that activates protease-activated receptors (PARs) to produce endothelium-derived relaxing factors such as nitric...
Plasmin is a fibrinolytic factor and a serine protease that activates protease-activated receptors (PARs) to produce endothelium-derived relaxing factors such as nitric oxide and prostacyclin. Nitric oxide and prostacyclin production is regulated, at least in part, by the intracellular Ca concentration in various blood vessel types. Bradykinin and plasmin stimulate vascular endothelial cells and work simultaneously in pathophysiological conditions such as thrombosis and inflammation. Here, we explored the interactions between bradykinin and plasmin in the endothelial Ca response using the fluorescent indicator, Fura-2/AM, in primary cultures of porcine aortic endothelial cells (PAECs). Plasmin (0.15-15 µg/ml) and bradykinin (0.1-10 nM) increased intracellular Ca concentrations in PAECs in a dose-dependent manner, and the plasmin-induced endothelial Ca response occurred only once. Bradykinin (0.1-10 nM) inhibited the plasmin-induced endothelial Ca response in a dose-dependent manner, however, plasmin did not affect the bradykinin-induced endothelial Ca response. Pretreatment with gabexate mesilate (GM, 100 µM), a serine protease inhibitor, that blocks plasmin's proteolytic activity, fully suppressed the plasmin-induced Ca response. After washout of GM and the first plasmin, the second administration of plasmin caused Ca increases. However, when the first plasmin-induced Ca response was blocked by pretreatment with bradykinin, the second plasmin (15 µg/ml) application did not cause any Ca response, even 30 min after the washout of the first plasmin and bradykinin. Our data suggested that bradykinin regulated the plasmin-induced endothelial Ca response by inhibiting the pathway downstream of the PARs' N-terminus cleavage.
Topics: Animals; Bradykinin; Calcium; Cells, Cultured; Dose-Response Relationship, Drug; Drug Interactions; Endothelial Cells; Endothelium, Vascular; Fibrinolysin; Fluorescent Dyes; Fura-2; Gabexate; Muscle Relaxation; Proteolysis; Serine Proteinase Inhibitors; Swine
PubMed: 29288468
DOI: 10.1007/s11010-017-3263-y -
Doklady. Biochemistry and Biophysics Nov 2021Plasminogen is a zymogenic form of plasmin, an enzyme that plays a fundamental role in the dissolution of fibrin clots as well as in many other physiological processes....
Plasminogen is a zymogenic form of plasmin, an enzyme that plays a fundamental role in the dissolution of fibrin clots as well as in many other physiological processes. For the first time, by the method of gas chromatography-mass spectrometry, post-translational modifications in the primary structure of plasminogen treated with physiologically relevant amounts of hydrogen peroxide were identified. It was found that methionine and tryptophan residues located in different structural regions of plasminogen served as targets of the oxidant. Plasminogen oxidation caused a dose-dependent effect in decreasing the fibrinogenolytic activity of plasmin evidenced by the formation of fibrinogen degradation products. The possible antioxidant role of methionines in the oxidative modification of plasminogen is discussed.
Topics: Fibrin; Fibrinogen; Fibrinolysin; Fibrinolysis; Oxidants; Peroxides; Plasminogen
PubMed: 34966964
DOI: 10.1134/S1607672921060053 -
ChemMedChem Nov 2022There is an emerging interest in utilizing synthetic multivalent inhibitors that comprise of multiple inhibitor moieties linked on a common scaffold to achieve strong...
There is an emerging interest in utilizing synthetic multivalent inhibitors that comprise of multiple inhibitor moieties linked on a common scaffold to achieve strong and selective enzyme inhibition. As multivalent inhibition is impacted by valency and linker length, in this study, we explore the effect of multivalent benzamidine inhibitors of varying valency and linker length on plasmin inhibition. Plasmin is an endogenous enzyme responsible for digesting fibrin present in blood clots. Monovalent plasmin(ogen) inhibitors are utilized clinically to treat hyperfibrinolysis-associated bleeding events. Benzamidine is a reversible inhibitor that binds to plasmin's active site. Herein, multivalent benzamidine inhibitors of varying valencies (mono-, bi- and tri-valent) and linker lengths (∼1-12 nm) were synthesized to systematically study their effect on plasmin inhibition. Inhibition assays were performed using a plasmin substrate (S-2251) to determine inhibition constants (Ki). Pentamidine (shortest bivalent) and Tri-AMB (shortest trivalent) were the strongest inhibitors with Ki values of 2.1±0.8 and 3.9±1.7 μM, respectively. Overall, increasing valency and decreasing linker length, increases effective local concentration of the inhibitor and therefore, resulted in stronger inhibition of plasmin via statistical rebinding. This study aids in the design of multivalent inhibitors that can achieve desired enzyme inhibition by means of modulating valency and linker length.
Topics: Fibrinolysin; Benzamidines
PubMed: 36111842
DOI: 10.1002/cmdc.202200364 -
Advances in Clinical and Experimental... 2017Vitreoretinal interface pathologies, such as vitreomacular traction syndrome, epiretinal membranes and macular holes are sight-threatening conditions and one of the... (Review)
Review
Vitreoretinal interface pathologies, such as vitreomacular traction syndrome, epiretinal membranes and macular holes are sight-threatening conditions and one of the important causes of vision defects and vision loss. To this date, vigilance with observation of how the vitreomacular traction resolves, or vitreoretinal surgery in more severe cases, were the only treatment options. Recent rapid progress in ophthalmology, especially in diagnostic and visualization techniques, provided better insight into the mechanisms taking place on the vitreoretinal surface, which enabled a more accurate selection of treatment options. Development of ophthalmic pharmacological procedures, such as treatment of vitreomacular traction syndrome with ocriplasmin, constitutes an innovative breakthrough in ophthalmology. The enzyme is a genetically engineered form of human plasmin, a component of blood coagulation cascade that has been envisioned for human therapy since 1950s. It has never been used for vitreolysis in ophthalmology before. The aim of this review is to analyze and compare therapeutic options for symptomatic vitreomacular adhesion and vitreoretinal traction, with particular emphasis on microplasmin. We reviewed the results of recent studies comparing ocriplasmin to other widespread treatment options, such as pars plana vitrectomy.
Topics: Female; Fibrinolysin; Humans; Peptide Fragments; Retinal Diseases; Retinal Perforations; Tissue Adhesions; Traction
PubMed: 28791829
DOI: 10.17219/acem/62122 -
Journal of Thrombosis and Haemostasis :... Nov 2018Essentials Activated clotting factor X (FXa) acquires fibrinolytic cofactor function after cleavage by plasmin. FXa-mediated plasma fibrinolysis is enabled by active...
UNLABELLED
Essentials Activated clotting factor X (FXa) acquires fibrinolytic cofactor function after cleavage by plasmin. FXa-mediated plasma fibrinolysis is enabled by active site modification blocking a second cleavage. FXa-directed oral anticoagulants (DOACs) alter FXa cleavage by plasmin. DOACs enhance FX-dependent fibrinolysis and plasmin generation by tissue plasminogen activator.
BACKGROUND
When bound to an anionic phospholipid-containing membrane, activated clotting factor X (FXa) is sequentially cleaved by plasmin from the intact form, FXaα, to FXaβ and then to Xa33/13. Tissue-type plasminogen activator (t-PA) produces plasmin and is the initiator of fibrinolysis. Both FXaβ and Xa33/13 enhance t-PA-mediated plasminogen activation. Although stable in experiments using purified proteins, Xa33/13 rapidly loses t-PA cofactor function in plasma. Bypassing this inhibition, covalent modification of the FXaα active site prevents Xa33/13 formation by plasmin, and the persistent FXaβ enhances plasma fibrinolysis. As the direct oral anticoagulants (DOACs) rivaroxaban and apixaban bind to the FXa active site, we hypothesized that they similarly modulate FXa fibrinolytic function.
METHODS
DOAC effects on fibrinolysis and the t-PA cofactor function of FXa were studied in patient plasma, normal pooled plasma and purified protein experiments by the use of light scattering, chromogenic assays, and immunoblots.
RESULTS
The plasma of patients taking rivaroxaban showed enhanced fibrinolysis correlating with FXaβ. In normal pooled plasma, the addition of rivaroxaban or apixaban also shortened fibrinolysis times. This was related to the cleavage product, FXaβ, which increased plasmin production by t-PA. It was confirmed that these results were not caused by DOACs affecting activated FXIII-mediated fibrin crosslinking, clot ultrastructure and thrombin-activatable fibrinolysis inhibitor activation in plasma.
CONCLUSION
The current study suggests a previously unknown effect of DOACs on FXa in addition to their well-documented anticoagulant role. By enabling the t-PA cofactor function of FXaβ in plasma, DOACs also enhance fibrinolysis. This effect may broaden their therapeutic indications.
Topics: Administration, Oral; Anticoagulants; Blood Coagulation; Catalytic Domain; Cross-Linking Reagents; Factor Xa; Factor Xa Inhibitors; Fibrin; Fibrinolysin; Fibrinolysis; Humans; Phospholipids; Pyrazoles; Pyridones; Rivaroxaban; Thrombin; Thrombolytic Therapy; Thrombosis; Tissue Plasminogen Activator
PubMed: 30176116
DOI: 10.1111/jth.14281 -
Molecular Oncology Jan 2024Aldehyde dehydrogenase 1A3 (ALDH1A3) is a cancer stem cell marker that promotes metastasis. Triple-negative breast cancer (TNBC) progression has been linked to...
Aldehyde dehydrogenase 1A3 (ALDH1A3) is a cancer stem cell marker that promotes metastasis. Triple-negative breast cancer (TNBC) progression has been linked to ALDH1A3-induced gene expression changes. To investigate the mechanism of ALDH1A3-mediated breast cancer metastasis, we assessed the effect of ALDH1A3 on the expression of proteases and the regulators of proteases that degrade the extracellular matrix, a process that is essential for invasion and metastasis. This revealed that ALDH1A3 regulates the plasminogen activation pathway; it increased the levels and activity of tissue plasminogen activator (tPA) and urokinase plasminogen activator (uPA). This resulted in a corresponding increase in the activity of serine protease plasmin, the enzymatic product of tPA and uPA. The ALDH1A3 product all-trans-retinoic acid similarly increased tPA and plasmin activity. The increased invasion of TNBC cells by ALDH1A3 was plasminogen-dependent. In patient tumours, ALDH1A3 and tPA are co-expressed and their combined expression correlated with the TNBC subtype, high tumour grade and recurrent metastatic disease. Knockdown of tPA in TNBC cells inhibited plasmin generation and lymph node metastasis. These results identify the ALDH1A3-tPA-plasmin axis as a key contributor to breast cancer progression.
Topics: Humans; Tissue Plasminogen Activator; Triple Negative Breast Neoplasms; Fibrinolysin; Aldehyde Dehydrogenase; Urokinase-Type Plasminogen Activator; Plasminogen; Melanoma
PubMed: 37753740
DOI: 10.1002/1878-0261.13528