Three-dimensional reconstruction of fibrin clot networks from stereoscopic intermediate voltage electron microscope images and analysis of branching

Baradet, Timothy; Haselgrove, John C.; Weisel, John W.

doi:10.1016/s0006-3495(95)80327-9

Cited by 75 publications

(76 citation statements)

References 24 publications

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“…Discrepancies between measurements obtained from confocal micrographs and scanning electron micrographs can be explained to some extent by the plasma origin of the fibrin clot in the present experiments. 22 However, another important difference may be also that our experiments dealt with fully hydrated fibrin instead of the dehydrated samples used in SEM. Dehydration leads to shrinkage of the native fibrin that artificially underestimates fibrin fiber diameter and fiber length and overestimates fiber density.…”

Section: Discussionmentioning

confidence: 99%

“…Dehydration leads to shrinkage of the native fibrin that artificially underestimates fibrin fiber diameter and fiber length and overestimates fiber density. 22 Moreover, the higher degree of stability of reflective samples than of fluorescent samples, which are typically more subject to thermal degradation and photobleaching, allowed us to perform dynamic experiments that were essential for the structural characterization of the fibrinolysis process, especially at the fiber level.…”

Section: Discussionmentioning

confidence: 99%

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Influence of Fibrin Network Conformation and Fibrin Fiber Diameter on Fibrinolysis Speed

Collet

Park

Lesty

et al. 2000

ATVB

443

427

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Abstract-Abnormal fibrin architecture is thought to be a determinant factor of hypofibrinolysis. However, because of the lack of structural knowledge of the process of fibrin digestion, relationships between fibrin architecture and hypofibrinolysis remain controversial. To elucidate further structural and dynamic changes occurring during fibrinolysis, cross-linked plasma fibrin was labeled with colloidal gold particles, and fibrinolysis was followed by confocal microscopy. Morphological changes were characterized at fibrin network and fiber levels. The observation of a progressive disaggregation of the fibrin fibers emphasizes that fibrinolysis proceeds by transverse cutting rather than by progressive cleavage uniformly around the fiber. Plasma fibrin clots with a tight fibrin conformation made of thin fibers were dissolved at a slower rate than those with a loose fibrin conformation made of thicker (coarse) fibers, although the overall fibrin content remained constant. Unexpectedly, thin fibers were cleaved at a faster rate than thick ones. A dynamic study of FITC-recombinant tissue plasminogen activator distribution within the fibrin matrix during the course of fibrinolysis showed that the binding front was broader in coarse fibrin clots and moved more rapidly than that of fine plasma fibrin clots. These dynamic and structural approaches to fibrin digestion at the network and the fiber levels reveal aspects of the physical process of clot lysis. Furthermore, these results provide a clear explanation for the hypofibrinolysis related to a defective fibrin architecture as described in venous thromboembolism and in premature coronary artery disease. Key Words: fibrin Ⅲ fibrinolysis Ⅲ confocal microscopy T he fibrin matrix has a much more complicated role than that of providing the scaffolding of the thrombus or being the target of fibrinolysis. Abnormal fibrin structure in vitro has been related to in vivo premature coronary artery disease in young patients and to severe venous thromboembolic disease in patients with dysfibrinogenemias. 1,2 In those situations, an abnormal fibrin matrix made up of abnormally thin fibers has been shown to promote hypofibrinolysis and embolization. Although much is known about the molecular basis of fibrinolysis, relationships between fibrin conformation and fibrinolysis need to be clarified.Fibrin actively regulates its self-dissolution through numerous interactions with fibrinolytic and antifibrinolytic components. Activation of plasminogen by tissue plasminogen activator (tPA) that is initiated on the conversion of fibrinogen into fibrin is a critical step that is affected by fibrin structure. The theory of a decrease of plasminogen binding to fibrin 3 has been strengthened from observations showing that clots with a fine fibrin (tight) conformation display a slower lysis rate than those with a coarse fibrin (loose) conformation. 2,4,5 So far, neither a molecular nor a structural basis has been detected for these differences. Moreover, a recent report demonstrates that under othe...

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Influence of Fibrin Network Conformation and Fibrin Fiber Diameter on Fibrinolysis Speed

Collet

Park

Lesty

et al. 2000

ATVB

443

427

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“…5,8,10,[16][17][18][19][20][21] In particular, the thrombin concentration influences both the fiber thickness and density of the fibrin clot. Low thrombin concentrations produce very turbid, highly permeable fibrin clots that are composed of thick, loosely-woven fibrin strands (Figure 1).…”

Section: Nih Public Accessmentioning

confidence: 99%

“…[10][11][12][13][14][15] The thrombin concentration influences fibrin clot formation, structure, and stability Fibrin clot structure depends on a number of variables, including pH, ionic strength, and concentrations of calcium, fibrinogen, and thrombin present during gelation. 5,8,10,[16][17][18][19][20][21] In particular, the thrombin concentration influences both the fiber thickness and density of the fibrin clot. Low thrombin concentrations produce very turbid, highly permeable fibrin clots that are composed of thick, loosely-woven fibrin strands (Figure 1).…”

Section: Fibrinogen and Fibrin Clot Formationmentioning

confidence: 99%

Thrombin generation, fibrin clot formation and hemostasis

Wolberg

Campbell

2008

Transfusion and Apheresis Science

279

222

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Hemostatic clot formation entails thrombin-mediated cleavage of fibrinogen to fibrin. Previous in vitro studies have shown that the thrombin concentration present during clot formation dictates the ultimate fibrin structure. In most prior studies of fibrin structure, clotting was initiated by adding thrombin to a solution of fibrinogen; however, clot formation in vivo occurs in an environment in which the concentration of free thrombin changes over the reaction course. These changes depend on local cellular properties and available concentrations of pro-and anti-coagulants. Recent studies suggest that abnormal thrombin generation patterns produce abnormally structured clots associated with an increased risk of bleeding or thrombosis. Further studies of fibrin formation during in situ thrombin generation are needed to understand fibrin clot formation in vivo. Keywordsthrombin; fibrinogen; fibrin; plasmin; fibrinolysis; clot structure; hemophilia; thrombosis Fibrinogen and fibrin clot formationFibrinogen is a 450 Å, 340 kDa trinodular protein present at high (2 -4 mg/mL) concentrations in plasma. Fibrinogen consists of pairs of three different disulfide-linked polypeptide chains: Aα, Bβ, and γ. These six polypeptide chains are arranged with their N-termini converged in a central "E" domain of the molecule. The C-termini of the Bβ and γ chains extend outward into distal "D" domains. The C-termini of the Aα chains are globular and situated near the central E domain of fibrinogen where they interact intra-molecularly. 1 Comprehensive reviews on the biochemistry of fibrinogen and fibrin structure have been published. 2-4Mechanisms of fibrin production have been elucidated in studies conducted by adding exogenous thrombin to purified fibrinogen. These studies have shown that thrombin removes N-terminal peptides from the fibrinogen Aαl and Bβ chains, causing the spontaneous formation of half-staggered, double-stranded protofibrils followed by thickening of protofibril chains. 5 Initial formation of protofibrils occurs during a "lag" phase in which no turbidity increase is detected. Subsequent lateral aggregation of fibrin protofibrils causes a turbidity increase. The magnitude of the turbidity increase relates to the structure of the formed clot; formation of thicker fibers causes a greater increase in final turbidity. 6,7 Fibrin formation can be followed Address correspondence to: Alisa Wolberg, Ph. D., Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, 815 Brinkhous-Bullitt Building, CB #7525, Chapel Hill, NC 27599-7525, phone: (919) 966-8430, fax: (919) 966-6718, email: alisa_wolberg@med.unc.edu. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production p...

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“…For example, scanning electron microscopy (SEM), involves a dehydration step in the preparation of the samples. This step is likely to cause fiber shrinkage, hampering a straightforward extraction of the fiber radius, although SEM still provides valuable quantitative information about the average length of the fibers or the branch density [29].…”

Section: Introductionmentioning

confidence: 99%

Fibrin structural and diffusional analysis suggests that fibers are permeable to solute transport

et al. 2017

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Three-dimensional reconstruction of fibrin clot networks from stereoscopic intermediate voltage electron microscope images and analysis of branching

Cited by 75 publications

References 24 publications

Influence of Fibrin Network Conformation and Fibrin Fiber Diameter on Fibrinolysis Speed

Influence of Fibrin Network Conformation and Fibrin Fiber Diameter on Fibrinolysis Speed

Thrombin generation, fibrin clot formation and hemostasis

Fibrin structural and diffusional analysis suggests that fibers are permeable to solute transport

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