Addendum: Kotál et al. Ixodes ricinus Salivary Serpin Iripin-8 Inhibits the Intrinsic Pathway of Coagulation and Complement. Int. J. Mol. Sci. 2021, 22, 9480

SummaryClots formed from platelet rich plasma were found to be lysed more readily by low concentrations of pro-urokinase (pro-UK) than clots formed from platelet poor plasma. This was not a non-specific effect since the reverse occurred with tissue plasminogen activator. A mechanical explanation due to platelet-mediated clot retraction was excluded by experiments in which retraction was inhibited with cyto-chalasin B. Therefore, a platelet-mediated enzymatic mechanism was postulated to explain the promotion of fibrinolysis. Casein autography of isolated platelets revealed a ≈ 90 kDa band of activity which comigrated with plasma prekallikrein (PK)/kallikrein, a known activator of pro-UK. Furthermore, treatment of platelets with plasma PK activator (PPA), consisting essentially of factor XIIa, induced activation of pro-UK and of chromomgenic substrate for kallikrein (S-2302). This activity corresponded to approximately 40-200 pM kallikrein per 10 8 washed and gel filtered platelets per ml. The activation of pro-UK by PPA-pretreated platelets was dose-dependent and inhibited by soybean trypsin inhibitor but not by bdellin, a specific inhibitor of plasmin, nor by the corn inhibitor of factor XIIa. Kinetic analysis of pro-UK activation by kallikrein showed promotion of the reaction by platelets. The KM of the reaction was reduced by platelets by ≈ 7-fold, while the kcat was essentially unchanged. In conclusion, PK was shown to be tightly associated with platelets where it can be activated by factor XIIa during clotting. The activation of pro-UK by platelet-bound kallikrein provides an explanation for the observed platelet mediated promotion of pro-UK-induced clot lysis. Since pro-UK and plasminogen have also been shown to be associated with platelets, the present findings suggest a mechanism by which the factor Xlla-dependent intrinsic pathway of fibrinolysis can be localized and targeted to a thrombus.

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Immunological Studies on the Blood Coagulation Factor X and Its Warfarin-induced Precursor

Thrombosis and Haemostasis ◽

10.1055/s-0038-1649144 ◽

1974 ◽

Vol 31 (01) ◽

pp. 040-051 ◽

Cited By ~ 5

Author(s):

Gustav Gaudernack ◽

Åse Gladhaug Berre ◽

Bjarne Østerud ◽

Hans Prydz

Keyword(s):

Coagulation Factor ◽

Factor X ◽

Intrinsic Pathway ◽

Coagulation Activity ◽

Factor X Deficiency ◽

Warfarin Treatment ◽

The Cross ◽

Monospecific Antisera ◽

Purified Antigen ◽

Congenital Factor

SummaryMonospecific antisera against the human coagulation factor X have been raised in rabbits by injections of purified antigen. Such antiserum was used to study the cross-reacting material without factor X activity which is present in the blood of warfarin-treated patients and animals as well as to study the changes in factor X during coagulation. One patient with congenital factor X deficiency was also studied.A complete identity was found between factor X in Macaca mulatta and human blood. During warfarin treatment antigenically cross-reacting material appeared in plasma. This was not adsorbed on BaSO4, and inhibited the coagulation activity of normal factor X.Both this material, normal factor X and the cross-reacting material in plasma from a patient congenitally deficient in factor X gave rise to split products during coagulation by the intrinsic pathway, i. e. all of them served as substrates for the intrinsic activator of factor X.

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Assembly and Activation of the Intrinsic Fibrinolytic Pathway on the Surface of Human Endothelial Cells in Culture

Thrombosis and Haemostasis ◽

10.1055/s-0038-1649800 ◽

1995 ◽

Vol 74 (02) ◽

pp. 698-703 ◽

Cited By ~ 29

Author(s):

Catherine Lenich ◽

Ralph Pannell ◽

Victor Gurewich

Keyword(s):

Endothelial Cells ◽

Umbilical Vein ◽

Factor Xii ◽

Plasminogen Activation ◽

High Molecular Weight Kininogen ◽

Human Endothelial Cells ◽

Intrinsic Pathway ◽

Local Fibrinolysis ◽

Umbilical Vein Endothelial Cells ◽

And Function

SummaryFactor XII has long been implicated in the intrinsic pathway of fibrinolysis, but the mechanism by which it triggers plasminogen activation and targets fibrinolysis has not been established. In the present study, the assembly and function of activated Factor XII (F.XIIa), prourokinase (pro-u-PA), high molecular weight kininogen (H-kininogen), and prekallikrein on human umbilical vein endothelial cells (HUVEC) was investigated. 125I-prekallikrein was shown to bind to HUVEC via receptor-bound H-kininogen in the presence of 50 μM ZnCl2. After the addition of F.XIIa, 78% of the 125I-prekallikrein initially bound to HUVEC was converted to 125I-kallikrein. However, only 6% of the HUVEC-bound 125I-pro-u-PA was thereby activated. This discrepancy was shown to be related to rapid dissociation (>50% within 15 min) of prekallikrein/kallikrein, but not pro-u-PA, from HUVEC. Increasing the level of cell-bound kallikrein increased the portion of cell-bound pro-u-PA activated, indicating that their co-localization was important for this pathway. Finally, F.XIIa was shown to trigger plasminogen activation on HUVEC via this pathway. This assembly of reactants on the endothelium suggests a mechanism whereby local fibrinolysis may be triggered by blood coagulation.

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Prostacyclin Synthesis Is Stimulated by a Serum Factor Formed During Coagulation

Thrombosis and Haemostasis ◽

10.1055/s-0038-1657316 ◽

1983 ◽

Vol 49 (01) ◽

pp. 058-060 ◽

Cited By ~ 12

Author(s):

J M Ritter ◽

M-A Ongari ◽

M A Orchard ◽

P J Lewis

Keyword(s):

Renal Failure ◽

Hydrolysis Product ◽

Healthy Controls ◽

Serum Factor ◽

Intrinsic Pathway ◽

Extrinsic Pathway ◽

Stimulatory Activity ◽

Plasma Factor ◽

Stimulating Factor ◽

Prostacyclin Synthesis

SummaryFresh aortic rings incubated in serum produce more 6-oxo-PGF1α, the stable hydrolysis product of prostacyclin, than in plasma or buffer. A method is described of recovering this stimulatory activity from a dialysate of serum, showing that the activity is due to a prostacyclin stimulating factor. This factor is formed during coagulation initiated by the intrinsic pathway but not by the extrinsic pathway or by thrombin. By contrast with a previously described plasma factor, the activity of the prostacy-clinstimulating factor in serum is not greater in serum from patients with renal failure than from healthy controls. The stimulating factor is antagonised by heparin, but differs in other ways from previously described platelet derived stimulating factor(s).

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TBE in Norway

Tick-borne encephalitis - The Book ◽

10.33442/978-981-14-0914-1_12b-24 ◽

2019 ◽

Author(s):

Katrine M. Paulsen ◽

Rose Vikse ◽

Arnulf Soleng ◽

Kristin S. Edgar ◽

Susanne Dudman ◽

...

Keyword(s):

Ixodes Ricinus ◽

Ixodes Ricinus Ticks

Ixodes ricinus ticks are mainly distributed along the Norwegian coastline from Østfold County in the southeast up approximately to 66°N in Nordland County.

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Defective Intrinsic Pathway for Apoptosis Due to p14ARF Loss of Function

Reactome ◽

10.3180/r-hsa-9645722.2 ◽

2019 ◽

Author(s):

Helen Rizos

Keyword(s):

Loss Of Function ◽

Intrinsic Pathway

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Magneto Mitochondrial Dysfunction Mediated Cancer Cell Death Using Intracellular Magnetic Nano-Transducers

Biomaterials Science ◽

10.1039/d1bm00419k ◽

2021 ◽

Author(s):

Wooram Park ◽

Seok-Jo Kim ◽

Paul Cheresh ◽

Jeanho Yun ◽

Byeongdu Lee ◽

...

Keyword(s):

Cell Death ◽

Cancer Therapy ◽

Mitochondrial Dysfunction ◽

Cancer Cells ◽

Cancer Cell ◽

High Sensitivity ◽

Intrinsic Pathway ◽

Cancer Cell Death

Mitochondria are crucial regulators of the intrinsic pathway of cancer cell death. The high sensitivity of cancer cells to mitochondrial dysfunction offers opportunities for emerging targets in cancer therapy. Herein,...

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