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International Journal of Molecular... Jan 2021Venous thrombosis occurs in patients with quantitative and qualitative fibrinogen disorders. Injury-induced thrombosis in zebrafish larvae has been used to model human...
Venous thrombosis occurs in patients with quantitative and qualitative fibrinogen disorders. Injury-induced thrombosis in zebrafish larvae has been used to model human coagulopathies. We aimed to determine whether zebrafish models of afibrinogenemia and dysfibrinogenemia have different thrombotic phenotypes. Laser injuries were used to induce venous thrombosis and the time-to-occlusion (TTO) and the binding and aggregation of fluorescent thrombocytes measured. The larvae failed to support occlusive venous thrombosis and showed reduced thrombocyte binding and aggregation at injury sites. The larvae were largely unaffected. When genome editing zebrafish to produce fibrinogen Aα R28C, equivalent to the human Aα R35C dysfibrinogenemia mutation, we detected in-frame skipping of exon 2 in the fga mRNA, thereby encoding Aα. This mutation is similar to Fibrinogen Montpellier II which causes hypodysfibrinogenemia. Aα fish had prolonged TTO and reduced thrombocyte activity, a dominant effect of the mutation. Finally, we used transgenic expression of fga R28C cDNA in fga knock-down or mutants to model thrombosis in dysfibrinogenemia. Aα R28C expression had similar effects on TTO and thrombocyte activity as Aα. We conclude that thrombosis assays in larval zebrafish can distinguish between quantitative and qualitative fibrinogen disorder models and may assist in anticipating a thrombotic phenotype of novel fibrinogen mutations.
Topics: Animals; Base Sequence; Biomarkers; Blood Coagulation; Blood Platelets; Disease Models, Animal; Exons; Fibrinogen; Gene Editing; Gene Expression; Plasmids; Platelet Activation; Sequence Deletion; Venous Thrombosis; Zebrafish; RNA, Guide, CRISPR-Cas Systems
PubMed: 33440782
DOI: 10.3390/ijms22020655 -
Journal of Thrombosis and Haemostasis :... Jun 2023Fibrinogen is a soluble, multisubunit, and multidomain dimeric protein, which, upon its proteolytic cleavage by thrombin, is converted to insoluble fibrin, initiating...
BACKGROUND
Fibrinogen is a soluble, multisubunit, and multidomain dimeric protein, which, upon its proteolytic cleavage by thrombin, is converted to insoluble fibrin, initiating polymerization that substantially contributes to clot growth. Fibrinogen contains numerous, transiently accessible "cryptic" epitopes for hemostatic and immunologic proteins, suggesting that fibrinogen exhibits conformational flexibility, which may play functional roles in its temporal and spatial interactions. Hitherto, there have been limited integrative approaches characterizing the solution structure and internal flexibility of fibrinogen.
METHODS
Here, utilizing a multipronged, biophysical approach involving 2 solution-based techniques, temperature-dependent hydrogen-deuterium exchange mass spectrometry and small angle X-ray scattering, corroborated by negative stain electron microscopy, we present a holistic, conformationally dynamic model of human fibrinogen in solution.
RESULTS
Our data reveal 4 major and distinct conformations of fibrinogen accommodated by a high degree of internal protein flexibility along its central scaffold. We propose that the fibrinogen structure in the solution consists of a complex, conformational landscape with multiple local minima. This is further supported by the location of numerous point mutations that are linked to dysfibrinogenemia and posttranslational modifications, residing near the identified fibrinogen flexions.
CONCLUSION
This work provides a molecular basis for the structural "dynamism" of fibrinogen that is expected to influence the broad swath of its functionally diverse macromolecular interactions and fine-tune the structural and mechanical properties of blood clots.
Topics: Humans; Fibrin Fibrinogen Degradation Products; Fibrin; Fibrinogen; Thrombosis; Molecular Conformation
PubMed: 36746319
DOI: 10.1016/j.jtha.2023.01.034 -
Journal of Clinical Laboratory Analysis Sep 2022We reported a patient with congenital dysfibrinogenemia who was misdiagnosed and reviewed relevant literature, in order to discuss the methods to reduce misdiagnosis. (Review)
Review
BACKGROUND
We reported a patient with congenital dysfibrinogenemia who was misdiagnosed and reviewed relevant literature, in order to discuss the methods to reduce misdiagnosis.
METHODS
A 23-year-old pregnant woman was found to be with low fibrinogen in antenatal examination at another province teaching hospital, who was misdiagnosed to have hypofibrinogenemia. Fibrinogen infusion or cryoprecipitation was recommended if necessary. The patient came to our hospital for further diagnosis and treatment considering the safety of herself and the fetus. We examined the coagulation function and gene sequencing of the pregnant woman and her family members.
RESULTS
Fibrinogen (Clauss method) was significantly reduced in the patient and her mother, while the level of fibrinogen (PT-derived method) was normal. Thrombin time was prolonged. Heterozygous mutation site was found in exon 2 of the FGA gene, c.104G > A(p.Arg35His).
CONCLUSION
When the fibrinogen (Clauss method) is significantly reduced and the thrombin time is prolonged, PT-derived method and the investigation of family coagulation function should be added, which can be used to diagnose and distinguish congenital dysfibrinogenemia from hypofibrinogenemia.
Topics: Adult; Afibrinogenemia; Diagnostic Errors; Exons; Female; Fibrinogen; Humans; Pregnancy; Young Adult
PubMed: 35949040
DOI: 10.1002/jcla.24624 -
JRSM Cardiovascular Disease 2020Chronic thromboembolic pulmonary hypertension is characterized by incomplete thrombus resolution following acute pulmonary embolism, leading to pulmonary hypertension...
PURPOSE
Chronic thromboembolic pulmonary hypertension is characterized by incomplete thrombus resolution following acute pulmonary embolism, leading to pulmonary hypertension and right ventricular dysfunction. Conditions such as thrombophilias, dysfibrinogenemias, and inflammatory states have been associated with chronic thromboembolic pulmonary hypertension, but molecular mechanisms underlying this disease are poorly understood. We sought to characterize the molecular and functional features associated with chronic thromboembolic pulmonary hypertension using a multifaceted approach.
METHODS
We utilized functional assays to compare clot lysis times between chronic thromboembolic pulmonary hypertension patients and multiple controls. We then performed immunohistochemical characterization of tissue from chronic thromboembolic pulmonary hypertension, pulmonary arterial hypertension, and healthy controls, and examined RNA expression patterns of cultured lymphocytes and pulmonary arterial specimens. We then confirmed RNA expression changes using immunohistochemistry, immunofluorescence, and Western blotting in pulmonary arterial tissue.
RESULTS
Clot lysis times in chronic thromboembolic pulmonary hypertension patients are similar to multiple controls. Chronic thromboembolic pulmonary hypertension endarterectomized tissue has reduced expression of both smooth muscle and endothelial cell markers. RNA expression profiles in pulmonary arteries and peripheral blood lymphocytes identified differences in RNA transcript levels related to inflammation and growth factor signaling, which we confirmed using immunohistochemistry. Gene expression data also suggested significant alterations in metabolic pathways, and immunofluorescence and Western blot experiments confirmed that unglycosylated CD36 and adiponectin expression were increased in chronic thromboembolic pulmonary hypertension versus controls.
CONCLUSIONS
Our data do not support impaired clot lysis underlying chronic thromboembolic pulmonary hypertension, but did demonstrate distinct molecular patterns present both in peripheral blood and in pathologic specimens of chronic thromboembolic pulmonary hypertension patients suggesting that altered metabolism may play a role in chronic thromboembolic pulmonary hypertension pathogenesis.
PubMed: 32110389
DOI: 10.1177/2048004020906994 -
Sichuan Da Xue Xue Bao. Yi Xue Ban =... Jan 2022To improve the understanding and diagnosis and treatment of congenital dysfibrinogenemia (CD) through analyzing the clinical data of a pediatric patient and his pedigree.
OBJECTIVE
To improve the understanding and diagnosis and treatment of congenital dysfibrinogenemia (CD) through analyzing the clinical data of a pediatric patient and his pedigree.
METHODS
The clinical manifestations, laboratory findings and treatment of a case of CD diagnosed at West China Second University Hospital, Sichuan University and those of its pedigree members were analyzed, and genetic tracing and follow-up were conducted on the patient and its pedigree.
RESULTS
The child has no clinical manifestations at the time of admission. Coagulation function examination showed normal prothrombin time (PT), normal activated partial thrombin time (APTT), significantly prolonged thrombin time (TT), fibrinogen activity (Fg: C<0.5 g/L) measured with the Clauss method, and fibrinogen antigen (Fg: Ag) measured at 2.8 g/L with PT algorithm. Gene sequencing results showed that heterozygous missense mutation c.901C>T (p.Arg301Cys) in exon 8 of gene. Combined with the family history, the child was diagnosed with CD. During the follow-up of 4 months, the patient did not present bleeding, abnormal coagulation or thrombosis, and the coagulation function did not show significant changes compared with the findings obtained on admission.
CONCLUSION
The diagnosis of CD is confirmed mainly based on genetic testing and the treatment is characterized by the principle of precise individualized treatment. No special treatment is needed for patients presenting no clinical manifestations. However, it is important to provide thorough prenatal diagnosis and follow-up services for female patients planning for pregnancy so as to prevent miscarriage and complications caused by postpartum coagulation dysfunction.
Topics: Afibrinogenemia; Child; Female; Fibrinogen; Heterozygote; Humans; Mutation; Pedigree
PubMed: 35048620
DOI: 10.12182/20220160201 -
Blood Coagulation & Fibrinolysis : An... Mar 2021Turbidity analysis is widely used as a quantitative technique in hereditary dysfibrinogenemia. We aimed to compare several coagulation triggers in hereditary... (Comparative Study)
Comparative Study
Turbidity analysis is widely used as a quantitative technique in hereditary dysfibrinogenemia. We aimed to compare several coagulation triggers in hereditary dysfibrinogenemia and control plasmas. We included 20 patients with hereditary dysfibrinogenemia, 19 with hotspot mutations Aα Arg35His (n = 9), Aα Arg35Cys (n = 2), γ Arg301His (n = 6), γ Arg301Cys (n = 2), and one with Aα Phe27Tyr, and a commercial pooled normal plasma. Fibrin polymerization was activated by bovine or human thrombin or tissue factor (TF), in the presence or absence of tissue type plasminogen activator. The lag time (min), slope (mOD/s), maximum absorbance (MaxAbs, mOD), and area under the curve (AUCp, OD s) were calculated from the fibrin polymerization curves and the time for 50% clot degradation (T50, min), AUCf (OD s) and the overall fibrinolytic potential from fibrinolysis curves. The lag time was significantly shorter and AUC increased in Aα Arg35His patients with bovine thrombin as compared with human thrombin. The MaxAbs and AUCp were significantly higher in γArg301His patients with bovine thrombin compared with human thrombin. Fibrin polymerization parameters of patients' samples were closer to those of control when assessed with TF compared with both human and bovine thrombin. T50 and overall fibrinolytic potential were similar in all samples regardless of the coagulation trigger used, however, with TF the AUCf of Aα Arg35His and γ Arg301His groups were significantly decreased compared with control. Bovine and human thrombin cannot be used equally for studying fibrin polymerization in hotspot hereditary dysfibrinogenemia or control plasmas.
Topics: Adolescent; Adult; Afibrinogenemia; Animals; Blood Coagulation; Blood Coagulation Tests; Cattle; Female; Fibrinogen; Humans; Indicators and Reagents; Male; Middle Aged; Mutation; Young Adult
PubMed: 33443927
DOI: 10.1097/MBC.0000000000001000 -
Thrombosis Research Feb 2019Clauss fibrinogen assay (CFA) is widely used as a screening test to detect fibrinogen disorders. However, CFA alone cannot distinguish quantitative and qualitative...
BACKGROUND
Clauss fibrinogen assay (CFA) is widely used as a screening test to detect fibrinogen disorders. However, CFA alone cannot distinguish quantitative and qualitative defects because it depends on functional fibrinogen activity (Ac), and fibrinogen antigen (Ag) determination is required to classify fibrinogen disorders.
OBJECTIVES
To establish a novel approach to classify fibrinogen disorders, we investigated the potential of clot waveform analysis (CWA) of CFA and searched for a surrogate marker for fibrinogen Ag.
MATERIALS AND METHODS
We analyzed CWA parameters obtained from CFA using plasma from normal patients (n = 91) and those with fibrinogen disorders (n = 27, including 15 hypofibrinogenemia, 6 dysfibrinogenemia and 6 hypodysfibrinogenemia) with a CS-5100 autoanalyzer.
RESULTS
We found that maximum coagulation velocity (Min1) levels were most strongly correlated with fibrinogen Ag in both normal and fibrinogen disorders. Hence, Min1 appeared to function as a surrogate for fibrinogen Ag. Although the Ac/Min1 ratio did not simply reflect the measured Ac/Ag ratio, we found that the Ac/Min1 ratio was significantly higher than normal in hypofibrinogenemia and hypodysfibrinogenemia, but not in dysfibrinogenemia. On the other hand, we could distinguish type II deficiency from type I using estimated fibrinogen Ag (eAg) predicted from Min1. The Ac/eAg ratios of dysfibrinogenemia and hypodysfibrinogenemia were significantly lower than those of normal and hypofibrinogenemia.
CONCLUSION
The CWA of CFA could distinguish fibrinogen disorders using a combination of Ac/Min1 and Ac/eAg values. This analysis allows the qualitative detection of fibrinogen disorder easily and represents a novel screening test for fibrinogen disorders.
Topics: Afibrinogenemia; Blood Coagulation Tests; Female; Fibrinogen; Hemostatics; Humans; Male
PubMed: 30584960
DOI: 10.1016/j.thromres.2018.12.018 -
International Journal of Laboratory... Apr 2021Congenital fibrinogen disorders (CFDs) are classified as afibrinogenemia or hypofibrinogenemia (Hypo), dysfibrinogenemia (Dys), or hypodysfibrinogenemia (Hypodys),...
INTRODUCTION
Congenital fibrinogen disorders (CFDs) are classified as afibrinogenemia or hypofibrinogenemia (Hypo), dysfibrinogenemia (Dys), or hypodysfibrinogenemia (Hypodys), according to functional and antigenic fibrinogen concentrations. However, in routine laboratory tests, plasma fibrinogen levels are mostly measured using the functional Clauss method and not as an antigenic level. Therefore, it is difficult to discriminate CFD from acquired hypofibrinogenemia (aHypo). To establish a screening method for CFD, we investigated the parameters of clot waveform analysis (CWA) from the Clauss method.
METHODS
We compared fibrinogen concentrations determined using Clauss and prothrombin time (PT)-derived methods for 67 aHypo and CFD cases (19 Dys, 4 Hypodys, and 1 Hypo determined using antigen levels and DNA sequence analysis) with a CS-2400 instrument, and the CWA parameters, dH and Min1, were analyzed automatically with an on-board algorithm. dH and Min1 are the maximum change in transmittance at the end of coagulation and the maximum velocity of transmittance change during coagulation, respectively.
RESULTS
Clauss/PT-derived ratios detected 18 cases of Dys and Hypodys but no Hypo cases, whereas Clauss/dH plus Clauss/Min1 ratios were calculated from fibrinogen concentration using the Clauss method and CWA parameters detected 21 cases of Dys and Hypodys and one Hypo case. Moreover, the Clauss/PT-derived ratio and Clauss/dH plus Clauss/Min1 ratio detected 22 cases of Dys and Hypodys cases and one Hypo case.
CONCLUSION
This report demonstrates that CWA parameters of the Clauss method, Clauss/dH plus Clauss/Min1 ratio, screened Dys patients with a higher rate, whereas Clauss/PT-derived ratios did not.
Topics: Adolescent; Adult; Afibrinogenemia; Aged; Aged, 80 and over; Biomarkers; Blood Coagulation; Blood Coagulation Tests; Child; Diagnostic Tests, Routine; Female; Fibrinogen; Humans; Male; Mass Screening; Middle Aged; Prothrombin Time; Young Adult
PubMed: 33030793
DOI: 10.1111/ijlh.13358 -
Zhonghua Xue Ye Xue Za Zhi = Zhonghua... Nov 2023To analyze the phenotype and genotype of two pedigrees with inherited fibrinogen (Fg) deficiency caused by two heterozygous mutations. We also preliminarily probed the...
To analyze the phenotype and genotype of two pedigrees with inherited fibrinogen (Fg) deficiency caused by two heterozygous mutations. We also preliminarily probed the molecular pathogenesis. The prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT) and plasma fibrinogen activity (Fg∶C) of all family members (nine people across three generations and three people across two generations) were measured by the clotting method. Fibrinogen antigen (Fg:Ag) was measured by immunoturbidimetry. Direct DNA sequencing was performed to analyze all exons, flanking sequences, and mutated sites of FGA, FGB, and FGG for all members. Thrombin-catalyzed fibrinogen polymerization was performed. ClustalX 2.1 software was used to analyze the conservatism of the mutated sites. MutationTaster, PolyPhen-2, PROVEAN, SIFT, and LRT online bioinformatics software were applied to predict pathogenicity. Swiss PDB Viewer 4.0.1 was used to analyze the changes in protein spatial structure and molecular forces before and after mutation. The Fg∶C of two probands decreased (1.28 g/L and 0.98 g/L, respectively). The Fg∶Ag of proband 1 was in the normal range of 2.20 g/L, while it was decreased to 1.01 g/L in proband 2. Through genetic analysis, we identified a heterozygous missense mutation (c.293C>A; p.BβAla98Asp) in exon 2 of proband 1 and a heterozygous nonsense mutation (c.1418C>G; p.BβSer473*) in exon 8 of proband 2. The conservatism analysis revealed that Ala98 and Ser473 presented different conservative states among homologous species. Online bioinformatics software predicted that p.BβAla98Asp and p.BβSer473* were pathogenic. Protein models demonstrated that the p.BβAla98Asp mutation influenced hydrogen bonds between amino acids, and the p.BβSer473* mutation resulted in protein truncation. The dysfibrinogenemia of proband 1 and the hypofibrinogenemia of proband 2 appeared to be related to the p.BβAla98Asp heterozygous missense mutation and the p.BβSer473* heterozygous nonsense mutation, respectively. This is the first ever report of these mutations.
Topics: Humans; Afibrinogenemia; Codon, Nonsense; Pedigree; Phenotype; Fibrinogen; Genotype
PubMed: 38185523
DOI: 10.3760/cma.j.issn.0253-2727.2023.11.008 -
Thrombosis Research Oct 2020
Topics: Afibrinogenemia; Blood Coagulation Tests; Fibrinogen; Hemostatics; Humans; Prothrombin Time
PubMed: 32788118
DOI: 10.1016/j.thromres.2020.07.023