scholarly journals Roles of fibrin α- and γ-chain specific cross-linking by FXIIIa in fibrin structure and function

2014 ◽  
Vol 111 (05) ◽  
pp. 842-850 ◽  
Author(s):  
Cédric Duval ◽  
Peter Allan ◽  
Simon D. A. Connell ◽  
Victoria C. Ridger ◽  
Helen Philippou ◽  
...  
Keyword(s):  
Potential Role ◽  
Fibrin Clot ◽  
Clot Formation ◽  
Cross Linking ◽  
Appearance Time ◽  
Lysis Rate ◽  
Α Chain ◽  
And Function ◽  
Clot Structure

SummaryFactor XIII is responsible for the cross-linking of fibrin γ-chains in the early stages of clot formation, whilst α-chain cross-linking occurs at a slower rate. Although γ- and α-chain cross-linking was previously shown to contribute to clot stiffness, the role of cross-linking of both chains in determining clot structure is currently unknown. Therefore, the aim of this study was to determine the role of individual α- and γ-chain cross-linking during clot formation, and its effects on clot structure. We made use of a recombinant fibrinogen (γQ398N/Q399N/K406R), which does not allow for y-chain cross-linking. In the absence of cross-linking, intact D-D interface was shown to play a potential role in fibre appearance time, clot stiffness and elasticity. Cross-linking of the fibrin α-chain played a role in the thickening of the fibrin fibres over time, and decreased lysis rate in the absence of α2-antiplasmin. We also showed that α-chain cross-linking played a role in the timing of fibre appearance, straightening fibres, increasing clot stiffness and reducing clot deformation. Cross-linking of the γ-chain played a role in fibrin fibre appearance time and fibre density. Our results show that α- and γ-chain cross-linking play independent and specific roles in fibrin clot formation and structure.

Polyphosphate Enhances Fibrin Clot Structure.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 403-403
Author(s):  
Stephanie A. Smith ◽  
James H. Morrissey
Keyword(s):  
High Energy ◽  
Fibrin Clot ◽  
Clot Formation ◽  
Length Ratio ◽  
Factor Xiiia ◽  
Clot Lysis ◽  
Cross Linking ◽  
Inorganic Polyphosphate ◽  
Calcium Dependent ◽  
Clot Structure

Abstract Introduction: Inorganic polyphosphate (polyP) is a negatively charged polymer of phosphate units linked by high energy phosphoanhydride bonds. Dense granules of human platelets contain polyP which is released in response to thrombin stimulation. We recently reported that polyphosphate is a potent hemostatic regulator, accelerating blood clotting by activating the contact pathway and promoting the activation of factor V. Our previous studies found that polyP did not affect the time to clot formation when plasma was clotted with thrombin, however, suggesting that polyP exerts its procoagulant actions upstream of thrombin. We now report that polyP enhances fibrin clot structure. Methods: Purified fibrinogen and polyP were preincubated for 15 min in multiwell plates in buffer containing CaCl2, after which clotting was initiated by adding 0.1 to 8 nM thrombin and fibrin clot formation was evaluated by quantifying the change in turbidity (A405). Mass-length ratios were calculated from scans of A400 to A800. The effect of polyP on fibrinolysis was examined by adding 8 nM plasmin to the reaction mixtures immediately prior to thrombin. Scanning electron microscopy (SEM) was employed to visualize clot structure, and time courses of covalent fibrin cross-linking were assessed by SDS-PAGE. Results: PolyP had no effect on time to clot formation, but clots formed in the presence of polyP had markedly (up to threefold) higher turbidity than clots formed in the absence of polyP (see figure), irrespective of thrombin concentration. The increased turbidity in the presence of polyP was calcium-dependent and was enhanced when fibrinogen, CaCl2, and polyP were preincubated for up to 15 min prior to initiation of clotting with thrombin. PolyP increased the mass-length ratio of fibrin, and SEM confirmed that fibers formed with polyP were thicker than those formed without polyP. The ability of polyP to enhance fibrin clot turbidity was independent of factor XIIIa activity, and polyP did not alter the rate or extent of covalent fibrin cross-linking by factor XIIIa. When plasmin was included in clotting reactions containing polyP, mean times to 50% clot lysis were 28.5 ± 0.8 min for clots without polyP but 120.4 ± 5.6 min for clots with polyP. Conclusions: PolyP alters polymerization of fibrin, resulting in fibers of higher mass-length ratio that are lysed more slowly. This effect is calcium-dependent and is enhanced by preincubation of fibrinogen with calcium and polyP. Release of polyP from activated platelets or infectious microorganisms may therefore enhance fibrin clot structure. Figure Figure

scholarly journals Enhanced lysis and accelerated establishment of viscoelastic properties of fibrin clots are associated with pulmonary embolism

2014 ◽  
Vol 306 (5) ◽  
pp. L397-L404 ◽  
Author(s):  
Marissa R. Martinez ◽  
Adam Cuker ◽  
Angela M. Mills ◽  
Amanda Crichlow ◽  
Richard T. Lightfoot ◽  
...  
Keyword(s):  
Pulmonary Embolism ◽  
Functional Properties ◽  
Viscoelastic Properties ◽  
Factor Xiii ◽  
Lag Time ◽  
Fibrin Clot ◽  
Clot Formation ◽  
Cross Linking ◽  
Clot Structure ◽  
Fibrin Clots

The factors that contribute to pulmonary embolism (PE), a potentially fatal complication of deep vein thrombosis (DVT), remain poorly understood. Whereas fibrin clot structure and functional properties have been implicated in the pathology of venous thromboembolism and the risk for cardiovascular complications, their significance in PE remains uncertain. Therefore, we systematically compared and quantified clot formation and lysis time, plasminogen levels, viscoelastic properties, activated factor XIII cross-linking, and fibrin clot structure in isolated DVT and PE subjects. Clots made from plasma of PE subjects showed faster clot lysis times with no differences in lag time, rate of clot formation, or maximum absorbance of turbidity compared with DVT. Differences in lysis times were not due to alterations in plasminogen levels. Compared with DVT, clots derived from PE subjects showed accelerated establishment of viscoelastic properties, documented by a decrease in lag time and an increase in the rate of viscoelastic property formation. The rate and extent of fibrin cross-linking by activated factor XIII were similar between clots from DVT and PE subjects. Electron microscopy revealed that plasma fibrin clots from PE subjects exhibited lower fiber density compared with those from DVT subjects. These data suggest that clot structure and functional properties differ between DVT and PE subjects and provide insights into mechanisms that may regulate embolization.

POPDC proteins and cardiac function

2019 ◽  
Vol 47 (5) ◽  
pp. 1393-1404 ◽  
Author(s):  
Thomas Brand
Keyword(s):  
Potential Role ◽  
Striated Muscle ◽  
Short Review ◽  
Effector Proteins ◽  
Muscle Disease ◽  
Disease Genes ◽  
Protein Protein Interaction ◽  
Interaction Partners ◽  
And Function

Abstract The Popeye domain-containing gene family encodes a novel class of cAMP effector proteins in striated muscle tissue. In this short review, we first introduce the protein family and discuss their structure and function with an emphasis on their role in cyclic AMP signalling. Another focus of this review is the recently discovered role of POPDC genes as striated muscle disease genes, which have been associated with cardiac arrhythmia and muscular dystrophy. The pathological phenotypes observed in patients will be compared with phenotypes present in null and knockin mutations in zebrafish and mouse. A number of protein–protein interaction partners have been discovered and the potential role of POPDC proteins to control the subcellular localization and function of these interacting proteins will be discussed. Finally, we outline several areas, where research is urgently needed.

Fibrin Formation: The Role of the Fibrinogen-Fibrin Monomer Complex

1976 ◽  
Vol 36 (01) ◽  
pp. 037-048 ◽  
Author(s):  
Eric P. Brass ◽  
Walter B. Forman ◽  
Robert V. Edwards ◽  
Olgierd Lindan
Keyword(s):  
Particle Size ◽  
Induction Period ◽  
Fibrin Clot ◽  
Clot Formation ◽  
Appreciable Amount ◽  
Buffer System ◽  
Homeostatic Mechanism ◽  
Fibrin Formation ◽  
Fibrin Monomer

SummaryThe process of fibrin formation using highly purified fibrinogen and thrombin was studied using laser fluctuation spectroscopy, a method that rapidly determines particle size in a solution. Two periods in fibrin clot formation were noted: an induction period during which no fibrin polymerization occurred and a period of rapid increase in particle size. Direct measurement of fibrin monomer polymerization and fibrinopeptide release showed no evidence of an induction period. These observations were best explained by a kinetic model for fibrin clot formation incorporating a reversible fibrinogen-fibrin monomer complex. In this model, the complex serves as a buffer system during the earliest phase of fibrin formation. This prevents the accumulation of free polymerizable fibrin monomer until an appreciable amount of fibrinogen has reacted with thrombin, at which point the fibrin monomer level rises rapidly and polymerization proceeds. Clinically, the complex may be a homeostatic mechanism preventing pathological clotting during periods of elevated fibrinogen.

scholarly journals Regarding “Altered fibrin clot structure and function in individuals with intermittent claudication”

2009 ◽  
Vol 49 (4) ◽  
pp. 1088-1089 ◽  
Author(s):  
Neeraj Bhasin ◽  
Duncan J. Parry ◽  
D. Julian A. Scott ◽  
Robert A.S. Ariëns ◽  
Peter J. Grant ◽  
...  
Keyword(s):  
Intermittent Claudication ◽  
Fibrin Clot ◽  
Structure And Function ◽  
And Function ◽  
Clot Structure

A novel natural mutation AαPhe98Ile in the fibrinogen coiled-coil affects fibrinogen function

2014 ◽  
Vol 111 (01) ◽  
pp. 79-87 ◽  
Author(s):  
Zuzana Riedelová-Reicheltová ◽  
Roman Kotlín ◽  
Jiří Suttnar ◽  
Věra Geierová ◽  
Tomáš Riedel ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Coiled Coil ◽  
Fibrin Clot ◽  
Coiled Coil Region ◽  
Platelet Aggregometry ◽  
Sds Page ◽  
Lysis Rate ◽  
Thrombotic Complications ◽  
Natural Mutation ◽  
And Function

SummaryThe aim of this study was to investigate the structure and function of fibrinogen obtained from a patient with normal coagulation times and idiopathic thrombophilia. This was done by SDS-PAGE and DNA sequence analyses, scanning electron microscopy, fibrinopeptide release, fibrin polymerisation initiated by thrombin and reptilase, fibrinolysis, and platelet aggregometry. A novel heterozygous point mutation in the fibrinogen Aα chain, Phe98 to Ile, was found and designated as fibrinogen Vizovice. The mutation, which is located in the RGDF sequence (Aα 95–98) of the fibrinogen coiled-coil region, significantly affected fibrin clot morphology. Namely, the clot formed by fibrinogen Vizovice contained thinner and curled fibrin fibers with reduced length. Lysis of the clots prepared from Vizovice plasma and isolated fibrinogen were found to be impaired. The lysis rate of Vizovice clots was almost four times slower than the lysis rate of control clots. In the presence of platelets agonists the mutant fibrinogen caused increased platelet aggregation. The data obtained show that natural mutation of Phe98 to Ile in the fibrinogen Aα chain influences lateral aggregation of fibrin protofibrils, fibrinolysis, and platelet aggregation. They also suggest that delayed fibrinolysis, together with the abnormal fibrin network morphology and increased platelet aggregation, may be the direct cause of thrombotic complications in the patient associated with pregnancy loss.

scholarly journals OX40L/OX40 Signal Promotes IL-9 Production by Mucosal MAIT Cells During Helicobacter pylori Infection

2021 ◽  
Vol 12 ◽  
Author(s):  
Siqi Ming ◽  
Mei Zhang ◽  
Zibin Liang ◽  
Chunna Li ◽  
Jianzhong He ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Potential Role ◽  
Critical Role ◽  
Underlying Mechanism ◽  
Mucosal Inflammation ◽  
Cross Linking ◽  
Mait Cells ◽  
H Pylori ◽  
Mait Cell

Mucosal associated invariant T (MAIT) cells play a critical role in Helicobacter pylori (H. pylori)-induced gastritis by promoting mucosal inflammation and aggravating mucosal injuries (1, 2). However, the underlying mechanism and key molecules involved are still uncertain. Here we identified OX40, a co-stimulatory molecule mainly expressed on T cells, as a critical regulator to promote proliferation and IL-9 production by MAIT cells and facilitate mucosal inflammation in H. pylori-positive gastritis patients. Serum examination revealed an increased level of IL-9 in gastritis patients. Meanwhile, OX40 expression was increased in mucosal MAIT cells, and its ligand OX40L was also up-regulated in mucosal dendritic cells (DCs) of gastritis patients, compared with healthy controls. Further results demonstrated that activation of the OX40/OX40L pathway promoted IL-9 production by MAIT cells, and MAIT cells displayed a highly-activated phenotype after the cross-linking of OX40 and OX40L. Moreover, the level of IL-9 produced by MAIT cells was positively correlated with inflammatory indexes in the gastric mucosa, suggesting the potential role of IL-9-producing MAIT cells in mucosal inflammation. Taken together, we elucidated that OX40/OX40L axis promoted mucosal MAIT cell proliferation and IL-9 production in H. pylori-induced gastritis, which may provide potential targeting strategies for gastritis treatment.

Fibrin Clot Structure and Function

2018 ◽  
pp. 31-49 ◽  
Author(s):  
Stephen R. Baker ◽  
Robert A.S. Ariëns
Keyword(s):  
Fibrin Clot ◽  
Structure And Function ◽  
And Function ◽  
Clot Structure

scholarly journals Endocrine Significance of SARS-CoV-2’s Reliance on ACE2

Endocrinology ◽  
2020 ◽  
Vol 161 (9) ◽  
Author(s):  
Eric Lazartigues ◽  
Mirza Muhammad Fahd Qadir ◽  
Franck Mauvais-Jarvis
Keyword(s):  
Potential Role ◽  
Renin Angiotensin System ◽  
Converting Enzyme ◽  
Angiotensin System ◽  
Angiotensin Converting Enzyme 2 ◽  
Global Impact ◽  
The Past ◽  
And Function ◽  
Endocrine Tissues

Abstract The current COVID-19 pandemic is the most disruptive event in the past 50 years, with a global impact on health care and world economies. It is caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), a coronavirus that uses angiotensin-converting enzyme 2 (ACE2) as an entry point to the cells. ACE2 is a transmembrane carboxypeptidase and member of the renin-angiotensin system. This mini-review summarizes the main findings regarding ACE2 expression and function in endocrine tissues. We discuss rapidly evolving knowledge on the potential role of ACE2 and SARS coronaviruses in endocrinology and the development of diabetes mellitus, hypogonadism, and pituitary and thyroid diseases.

scholarly journals The Potential Role of Seminal Plasma in the Fertilization Outcomes

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Justyna Szczykutowicz ◽  
Anna Kałuża ◽  
Maria Kaźmierowska-Niemczuk ◽  
Mirosława Ferens-Sieczkowska
Keyword(s):  
Seminal Plasma ◽  
Potential Role ◽  
Human Sperm ◽  
Structure And Function ◽  
Regulatory Mechanisms ◽  
Male And Female ◽  
Healthy Pregnancy ◽  
Male Gametes ◽  
And Function

For human infertility both male and female factors may be equally important. Searching for molecular biomarkers of male infertility, neglected for decades, and the attempts to explain regulatory mechanisms of fertilization become thus extremely important. Apart from examination of the structure and function of male gametes, also the possible importance of seminal plasma components should be considered. In this article we discuss data that indicate for the substantial significance of active seminal plasma components for conception and achievement of healthy pregnancy. Seminal plasma impact on the storage and cryopreservation of human and animal sperm and regulatory role of glycodelin on human sperm capacitation as well as hypothesized course of female immune response to allogenic sperm and conceptus has been discussed. The possible involvement of carbohydrates in molecular mechanism of fetoembryonic defense has been also mentioned.

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