scholarly journals Genetic Variants in the FGB and FGG Genes Mapping in the Beta and Gamma Nodules of the Fibrinogen Molecule in Congenital Quantitative Fibrinogen Disorders Associated with a Thrombotic Phenotype

2020 ◽  
Vol 21 (13) ◽  
pp. 4616
Author(s):  
Tomas Simurda ◽  
Monika Brunclikova ◽  
Rosanna Asselta ◽  
Sonia Caccia ◽  
Jana Zolkova ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Clinical Manifestations ◽  
Cell Interaction ◽  
Fibrin Clot ◽  
Congenital Defects ◽  
Blood Clots ◽  
Life Threatening ◽  
Congenital Afibrinogenemia ◽  
Insoluble Polymer ◽  
Fibrinogen Molecule

Fibrinogen is a hexameric plasmatic glycoprotein composed of pairs of three chains (Aα, Bβ, and γ), which play an essential role in hemostasis. Conversion of fibrinogen to insoluble polymer fibrin gives structural stability, strength, and adhesive surfaces for growing blood clots. Equally important, the exposure of its non-substrate thrombin-binding sites after fibrin clot formation promotes antithrombotic properties. Fibrinogen and fibrin have a major role in multiple biological processes in addition to hemostasis and thrombosis, i.e., fibrinolysis (during which the fibrin clot is broken down), matrix physiology (by interacting with factor XIII, plasminogen, vitronectin, and fibronectin), wound healing, inflammation, infection, cell interaction, angiogenesis, tumour growth, and metastasis. Congenital fibrinogen deficiencies are rare bleeding disorders, characterized by extensive genetic heterogeneity in all the three genes: FGA, FGB, and FGG (enconding the Aα, Bβ, and γ chain, respectively). Depending on the type and site of mutations, congenital defects of fibrinogen can result in variable clinical manifestations, which range from asymptomatic conditions to the life-threatening bleeds or even thromboembolic events. In this manuscript, we will briefly review the main pathogenic mechanisms and risk factors leading to thrombosis, and we will specifically focus on molecular mechanisms associated with mutations in the C-terminal end of the beta and gamma chains, which are often responsible for cases of congenital afibrinogenemia and hypofibrinogenemia associated with thrombotic manifestations.

scholarly journals Is Tolerance Broken in Autoimmunity?

2017 ◽  
Vol 10 ◽  
pp. 117955571771271
Author(s):  
Dama Laxminarayana
Keyword(s):  
Autoimmune Diseases ◽  
Molecular Mechanisms ◽  
Clinical Manifestations ◽  
Symptomatic Treatment ◽  
Cellular Events ◽  
Life Threatening ◽  
Benign Disorders ◽  
Autoimmune Pathogenesis ◽  
System Organ

Autoimmune diseases are classified into about 80 different types based on their specificity related to system, organ and/or tissue. About 5% of the western population is affected by this anomaly, but its worldwide incidence is unknown. Autoimmune diseases are heterogeneous in nature and clinical manifestations range from benign disorders to life-threatening conditions. Autoimmunity strikes at any stage of life, but age and/or gender also play role in onset of some of these anomalies. The autoimmune pathogenesis is initiated by the origination of autoantigens, which leads to the development of autoantibodies followed by auto-immunogenicity and the ultimate onset of autoimmunity. There is a lack of suitable therapies to treat autoimmune diseases, because mechanisms involved in the onset of these anomalies were poorly understood. Present therapies are limited to symptomatic treatment and come with severe side effects. Here, I described the molecular mechanisms and cellular events involved in the initiation of autoimmunity and proposed better strategies to modulate such molecular and cellular anomalies, which will help in preventing and/or controlling autoimmune pathogenesis and ultimately aid in enhancing the quality of life.

scholarly journals Viral Respiratory Pathogens and Lung Injury

2021 ◽  
Vol 34 (3) ◽  
Author(s):  
Nicola Clementi ◽  
Sreya Ghosh ◽  
Maria De Santis ◽  
Matteo Castelli ◽  
Elena Criscuolo ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Cell Damage ◽  
Clinical Manifestations ◽  
Upper Airway ◽  
Patient Specific ◽  
Respiratory Pathogens ◽  
Human Respiratory Tract ◽  
Immune Mediated ◽  
Life Threatening ◽  
Viral Respiratory

SUMMARY Several viruses target the human respiratory tract, causing different clinical manifestations spanning from mild upper airway involvement to life-threatening acute respiratory distress syndrome (ARDS). As dramatically evident in the ongoing SARS-CoV-2 pandemic, the clinical picture is not always easily predictable due to the combined effect of direct viral and indirect patient-specific immune-mediated damage. In this review, we discuss the main RNA (orthomyxoviruses, paramyxoviruses, and coronaviruses) and DNA (adenoviruses, herpesviruses, and bocaviruses) viruses with respiratory tropism and their mechanisms of direct and indirect cell damage. We analyze the thin line existing between a protective immune response, capable of limiting viral replication, and an unbalanced, dysregulated immune activation often leading to the most severe complication. Our comprehension of the molecular mechanisms involved is increasing and this should pave the way for the development and clinical use of new tailored immune-based antiviral strategies.

scholarly journals Congenital Afibrinogenemia and Hypofibrinogenemia: Laboratory and Genetic Testing in Rare Bleeding Disorders with Life-Threatening Clinical Manifestations and Challenging Management

Diagnostics ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2140
Author(s):  
Tomas Simurda ◽  
Rosanna Asselta ◽  
Jana Zolkova ◽  
Monika Brunclikova ◽  
Miroslava Dobrotova ◽  
...  
Keyword(s):  
Genetic Testing ◽  
Clinical Phenotype ◽  
Clinical Manifestations ◽  
Compound Heterozygous ◽  
Genes Encoding ◽  
Life Threatening ◽  
Congenital Afibrinogenemia ◽  
Thrombotic Complications ◽  
Based Medicine ◽  
Processing Stability

Congenital fibrinogen disorders are rare pathologies of the hemostasis, comprising quantitative (afibrinogenemia, hypofibrinogenemia) and qualitative (dysfibrinogenemia and hypodysfibrinogenemia) disorders. The clinical phenotype is highly heterogeneous, being associated with bleeding, thrombosis, or absence of symptoms. Afibrinogenemia and hypofibrinogenemia are the consequence of mutations in the homozygous, heterozygous, or compound heterozygous state in one of three genes encoding the fibrinogen chains, which can affect the synthesis, assembly, intracellular processing, stability, or secretion of fibrinogen. In addition to standard coagulation tests depending on the formation of fibrin, diagnostics also includes global coagulation assays, which are effective in monitoring the management of replacement therapy. Genetic testing is a key point for confirming the clinical diagnosis. The identification of the precise genetic mutations of congenital fibrinogen disorders is of value to permit early testing of other at risk persons and better understand the correlation between clinical phenotype and genotype. Management of patients with afibrinogenemia is particularly challenging since there are no data from evidence-based medicine studies. Fibrinogen concentrate is used to treat bleeding, whereas for the treatment of thrombotic complications, administered low-molecular-weight heparin is most often. This review deals with updated information about afibrinogenemia and hypofibrinogenemia, contributing to the early diagnosis and effective treatment of these disorders.

scholarly journals Accelerated Spatial Fibrin Growth and Impaired Contraction of Blood Clots in Patients with Rheumatoid Arthritis

2020 ◽  
Vol 21 (24) ◽  
pp. 9434
Author(s):  
Alina D. Peshkova ◽  
Tatiana A. Evdokimova ◽  
Timur B. Sibgatullin ◽  
Fazoil I. Ataullakhanov ◽  
Rustem I. Litvinov ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Binding Capacity ◽  
Blood Clot ◽  
Clinical Manifestations ◽  
Fibrin Clot ◽  
Control Group ◽  
Plasma Clot ◽  
Blood Clots ◽  
Clot Contraction ◽  
Hemostatic Disorders

Rheumatoid arthritis (RA) is an autoimmune disease associated with thrombotic complications. To elucidate pathogenic mechanisms, hemostatic disorders in RA were correlated with other laboratory and clinical manifestations. Hemostasis was assessed using relatively new complementary tests, the spatial growth of a plasma clot (Thrombodynamics assay), and contraction of whole blood clots. Platelet functionality was assessed with flow cytometry that quantified the expression of P-selectin and the fibrinogen-binding capacity of platelets before and after activation with a thrombin receptor-activating peptide. Parameters of fibrin clot growth and the kinetics of contraction of blood clots were significantly altered in patients with RA compared to the control group. In Thrombodynamics measurements, an increase in the clot growth rate, size, and optical density of plasma clots altogether indicated chronic hypercoagulability. The rate and extent of blood clot contraction in patients with RA was significantly reduced and associated with platelet dysfunction revealed by an impaired response to activation. Changes in the parameters of clot growth and contraction correlated with the laboratory signs of systemic inflammation, including hyperfibrinogenemia. These results confirm the pathogenic role of hemostatic disorders in RA and support the validity of fibrin clot growth and the blood clot contraction assay as indicators of a (pro)thrombotic state.

scholarly journals Animal Model of Severe Fever With Thrombocytopenia Syndrome Virus Infection

2022 ◽  
Vol 12 ◽  
Author(s):  
Jiawen Sun ◽  
Yuan-Qin Min ◽  
Yunjie Li ◽  
Xiulian Sun ◽  
Fei Deng ◽  
...  
Keyword(s):  
Animal Models ◽  
Molecular Mechanisms ◽  
Clinical Manifestations ◽  
Medical Problem ◽  
Future Research ◽  
Antiviral Therapies ◽  
Treatment And Prevention ◽  
Animal Infection ◽  
Life Threatening ◽  
Severe Fever

Severe fever with thrombocytopenia syndrome (SFTS), an emerging life-threatening infectious disease caused by SFTS bunyavirus (SFTSV; genus Bandavirus, family Phenuiviridae, order Bunyavirales), has been a significant medical problem. Currently, there are no licensed vaccines or specific therapeutic agents available and the viral pathogenesis remains largely unclear. Developing appropriate animal models capable of recapitulating SFTSV infection in humans is crucial for both the study of the viral pathogenic processes and the development of treatment and prevention strategies. Here, we review the current progress in animal models for SFTSV infection by summarizing susceptibility of various potential animal models to SFTSV challenge and the clinical manifestations and histopathological changes in these models. Together with exemplification of studies on SFTSV molecular mechanisms, vaccine candidates, and antiviral drugs, in which animal infection models are utilized, the strengths and limitations of the existing SFTSV animal models and some important directions for future research are also discussed. Further exploration and optimization of SFTSV animal models and the corresponding experimental methods will be undoubtedly valuable for elucidating the viral infection and pathogenesis and evaluating vaccines and antiviral therapies.

Properties of Fibrinogen Cleaved by Jararhagin, a Metalloproteinase from the Venom of Bothrops jararaca

1994 ◽  
Vol 72 (02) ◽  
pp. 244-249 ◽  
Author(s):  
Aura S Kamiguti ◽  
Joseph R Slupsky ◽  
Mirko Zuzel ◽  
Charles R M Hay
Keyword(s):  
Platelet Aggregation ◽  
Platelet Function ◽  
Fibrin Clot ◽  
Clot Formation ◽  
Human Fibrinogen ◽  
Activated Platelets ◽  
Bothrops Jararaca ◽  
Platelet Binding ◽  
Fibrin Monomers ◽  
Fibrinogen Molecule

SummaryHaemorrhagic metalloproteinases from Bothrops jararaca and other venoms degrade vessel-wall and plasma proteins involved in platelet plug and fibrin clot formation. These enzymes also cause proteolytic digestion of fibrinogen which has been suggested to cause defective platelet function. Fibrinogen degradation by jararhagin, a metalloproteinase from B. jararaca, and the effect of jararhagin fibrinogenolysis on both platelet aggregation and fibrin clot formation were investigated. Jararhagin was found to cleave human fibrinogen in the C-terminal region of the Aα-chain giving rise to a 285-290 kDa fibrinogen molecule lacking the Aα-chain RGD 572-574 platelet-binding site. Platelet binding and aggregation of ADP-activated platelets is unaffected by this modification. This indicates that the lost site is not essential for platelet aggregation, and that the remaining platelet binding sites located in the N-terminal portion of Aα chains (RGD 95-97) and the C-terminal of γ chains (dodecapeptide 400-411) are unaffected by jararhagin-digestion of fibrinogen. Fibrin clot formation with thrombin of this remnant fibrinogen molecule was defective, with poor polymerization of fibrin monomers but normal release of FPA. The abnormal polymerization could be explained by the loss of one of the two complementary polymerization sites required for side-by-side association of fibrin protofibrils. Jararhagin-induced inhibition of platelet function, an important cause of haemorrhage in envenomed patients, is not caused by proteolysis of fibrinogen, as had been thought, and the mechanism remains to be elucidated.

scholarly journals Impairing flow-mediated endothelial remodeling reduces extravasation of tumor cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Gautier Follain ◽  
Naël Osmani ◽  
Valentin Gensbittel ◽  
Nandini Asokan ◽  
Annabel Larnicol ◽  
...  
Keyword(s):  
Blood Flow ◽  
Tumor Cells ◽  
Molecular Mechanisms ◽  
Metastatic Progression ◽  
Metastatic Dissemination ◽  
Secondary Tumors ◽  
Flow Profiles ◽  
Endothelial Response ◽  
Life Threatening

AbstractTumor progression and metastatic dissemination are driven by cell-intrinsic and biomechanical cues that favor the growth of life-threatening secondary tumors. We recently identified pro-metastatic vascular regions with blood flow profiles that are permissive for the arrest of circulating tumor cells. We have further established that such flow profiles also control endothelial remodeling, which favors extravasation of arrested CTCs. Yet, how shear forces control endothelial remodeling is unknown. In the present work, we aimed at dissecting the cellular and molecular mechanisms driving blood flow-dependent endothelial remodeling. Transcriptomic analysis of endothelial cells revealed that blood flow enhanced VEGFR signaling, among others. Using a combination of in vitro microfluidics and intravital imaging in zebrafish embryos, we now demonstrate that the early flow-driven endothelial response can be prevented upon specific inhibition of VEGFR tyrosine kinase and subsequent signaling. Inhibitory targeting of VEGFRs reduced endothelial remodeling and subsequent metastatic extravasation. These results confirm the importance of VEGFR-dependent endothelial remodeling as a driving force of CTC extravasation and metastatic dissemination. Furthermore, the present work suggests that therapies targeting endothelial remodeling might be a relevant clinical strategy in order to impede metastatic progression.

Fabry disease: from clinical manifestations to molecular mechanisms

2007 ◽  
Vol 91 ◽  
pp. 119-119
Author(s):  
K Azibi ◽  
C Heltianu ◽  
C Caillaud ◽  
J Manicom ◽  
JP Puech ◽  
...  
Keyword(s):  
Fabry Disease ◽  
Molecular Mechanisms ◽  
Clinical Manifestations

scholarly journals Pathophysiology of Atherosclerotic Plaque Development-Contemporary Experience and New Directions in Research

2021 ◽  
Vol 22 (7) ◽  
pp. 3513
Author(s):  
Michal Kowara ◽  
Agnieszka Cudnoch-Jedrzejewska
Keyword(s):  
Atherosclerotic Plaque ◽  
Molecular Mechanisms ◽  
Cellular Heterogeneity ◽  
Ldl Oxidation ◽  
Plaque Development ◽  
New Directions ◽  
Life Threatening ◽  
Non Coding Rnas ◽  
Cellular Pathways ◽  
Key Aspects

Atherosclerotic plaque is the pathophysiological basis of important and life-threatening diseases such as myocardial infarction. Although key aspects of the process of atherosclerotic plaque development and progression such as local inflammation, LDL oxidation, macrophage activation, and necrotic core formation have already been discovered, many molecular mechanisms affecting this process are still to be revealed. This minireview aims to describe the current directions in research on atherogenesis and to summarize selected studies published in recent years—in particular, studies on novel cellular pathways, epigenetic regulations, the influence of hemodynamic parameters, as well as tissue and microorganism (microbiome) influence on atherosclerotic plaque development. Finally, some new and interesting ideas are proposed (immune cellular heterogeneity, non-coding RNAs, and immunometabolism) which will hopefully bring new discoveries in this area of investigation.

scholarly journals Classification of lymphoid neoplasms: the microscope as a tool for disease discovery

Blood ◽  
2008 ◽  
Vol 112 (12) ◽  
pp. 4384-4399 ◽  
Author(s):  
Elaine S. Jaffe ◽  
Nancy Lee Harris ◽  
Harald Stein ◽  
Peter G. Isaacson
Keyword(s):  
Molecular Mechanisms ◽  
Nk Cell ◽  
Clinical Manifestations ◽  
Lymphoid Cells ◽  
World Health ◽  
International Studies ◽  
Lymphocyte Function ◽  
Lymphoid Neoplasms

AbstractIn the past 50 years, we have witnessed explosive growth in the understanding of normal and neoplastic lymphoid cells. B-cell, T-cell, and natural killer (NK)–cell neoplasms in many respects recapitulate normal stages of lymphoid cell differentiation and function, so that they can be to some extent classified according to the corresponding normal stage. Likewise, the molecular mechanisms involved the pathogenesis of lymphomas and lymphoid leukemias are often based on the physiology of the lymphoid cells, capitalizing on deregulated normal physiology by harnessing the promoters of genes essential for lymphocyte function. The clinical manifestations of lymphomas likewise reflect the normal function of lymphoid cells in vivo. The multiparameter approach to classification adopted by the World Health Organization (WHO) classification has been validated in international studies as being highly reproducible, and enhancing the interpretation of clinical and translational studies. In addition, accurate and precise classification of disease entities facilitates the discovery of the molecular basis of lymphoid neoplasms in the basic science laboratory.

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