Evidence for QTLs Influencing the Endogenous Thrombin Potential (ETP) and Protein C Concentrations in a Dutch Family with Unexplained Thrombophilia.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 132-132
Author(s):  
Michael W.T. Tanck ◽  
Iris M. Wichers ◽  
Joost C.M. Meijers ◽  
Harry R. Büller ◽  
Pieter H. Reitsma ◽  
...  
Keyword(s):  
Protein C ◽  
Extended Family ◽  
Coagulation Factors ◽  
Coagulation Cascade ◽  
Phenotypic Data ◽  
Endogenous Thrombin Potential ◽  
Chromosome 20 ◽  
A Genome ◽  
Bivariate Linkage Analysis ◽  
Dutch Family

Abstract Introduction: In Dutch families with unexplained thrombophilia (GENES study), plasma levels of the endogenous thrombin potential (ETP) discriminated affected from non-affected family members. A high variance, i.e. >60%, attributable to genetic factors was found for the ETP in one extended family. Increases in ETP levels could not be readily explained by known determinants of ETP from the coagulation cascade or anticoagulant pathways. In the present study, a genome-wide scan was performed in this family to identify quantitative trait loci (QTL) influencing ETP and several other coagulation factors. Methods: Phenotypic data, plasma, and DNA were available for 135 of the 185 individuals in the pedigree. Patients using anticoagulation medication were excluded from the analyses. If necessary, data were transformed prior to the analyses. Multipoint Identity by Descent (IBD)-estimation and variance component multipoint (bivariate) linkage analysis including covariates were performed using SOLAR. LOD scores were empirically adjusted. Results: For ETP levels, suggestive evidence for linkage was found at 36 cM (one-lod support interval: 1 – 61 cM) on chromosome 20 (LOD = 2.57). Interestingly, significant evidence for linkage with protein C levels (LOD=6.6) was found in the same region at 48 cM (41 – 59 cM). A bivariate LOD score of 5.8 (p<2x10−6) was obtained for this region of chromosome 20, but the correlation between the two traits due to QTL effects was low (0.10 ± 0.28, p=0.734). This finding, together with the fact that the test for complete pleiotropy had to be rejected (p<0.0001), indicates that ETP and protein C levels are most likely influenced by two different QTLs (i.e. coincident linkage) on chromosome 20. Conclusion: In this Dutch family, ETP and protein C levels were influenced by two putative major genes, both localized in the same region of chromosome 20. This region is known to harbor several liver-enriched transcription factors, e.g. hepatocyte nuclear factor (HNF) 3b (20p11) and HNF4a (20q12-q13.1). Since most of the plasma proteins that determine the level of ETP are synthesized in the liver, these candidate genes are now further explored within this family with unexplained thrombophilia and inherited high ETP levels.

scholarly journals Cryo-EM structures of human coagulation factors V and Va

Blood ◽  
2021 ◽  
Author(s):  
Eliza A Ruben ◽  
Michael J Rau ◽  
James Fitzpatrick ◽  
Enrico Di Cera
Keyword(s):  
Protein C ◽  
Activated Protein C ◽  
Factor Xa ◽  
Coagulation Factor ◽  
Coagulation Factors ◽  
Proteolytic Processing ◽  
Coagulation Cascade ◽  
Factor V ◽  
Prothrombinase Complex ◽  
A2 Domain

Coagulation factor V is the precursor of factor Va that, together with factor Xa, Ca2+ and phospholipids, defines the prothrombinase complex and activates prothrombin in the penultimate step of the coagulation cascade. Here we present cryo-EM structures of human factors V and Va at atomic (3.3 Å) and near-atomic (4.4 Å) resolution, respectively. The structure of fV reveals the entire A1-A2-B-A3-C1-C2 assembly but with a surprisingly disordered B domain. The C1 and C2 domains provide a platform for interaction with phospholipid membranes and support the A1 and A3 domains, with the A2 domain sitting on top of them. The B domain is highly dynamic and visible only for short segments connecting to the A2 and A3 domains. The A2 domain reveals all sites of proteolytic processing by thrombin and activated protein C, a partially buried epitope for binding factor Xa and fully exposed epitopes for binding activated protein C and prothrombin. Removal of the B domain and activation to fVa exposes the sites of cleavage by activated protein C at R306 and R506 and produces increased disorder in the A1-A2-A3-C1-C2 assembly, especially in the C-terminal acidic portion of the A2 domain responsible for prothrombin binding. Ordering of this region and full exposure of the factor Xa epitope emerge as a necessary step for the assembly of the prothrombin-prothrombinase complex. These structures offer molecular context for the function of factors V and Va and pioneer the analysis of coagulation factors by cryo-EM.

Increased Plasma Levels of Tissue Factor Associated to Thrombomodulin Resistance in Patients with Advanced Liver Cirrhosis

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1094-1094 ◽  
Author(s):  
Patrick Van Dreden ◽  
Sophie Hillaire ◽  
Matthieu Grusse ◽  
Dominique François ◽  
Catherine Gorin ◽  
...  
Keyword(s):  
Tissue Factor ◽  
Protein C ◽  
Anticoagulant Activity ◽  
Severe Disease ◽  
Coagulation Factors ◽  
Significant Negative Correlation ◽  
Lag Time ◽  
Disease Stage ◽  
Coagulation Cascade ◽  
Cirrhotic Patients

Abstract Background: Despite reduced coagulation factors, it was recently described that patients with cirrhosis have an increased thrombotic tendency. Therefore, assays predicting the risk of bleeding or thrombosis are needed. Aims: As the Tissue Factor (TF) pathway plays a major role in the initiation of the coagulation, we evaluated the equilibrium between Tissue Factor activity (TFa) and Tissue Factor Pathway Inhibitor (TFPI) and their relationship with the thrombin generation (TG) assay in 42 cirrhotic patients. TG was realized in the absence and presence of thrombomodulin (TM), since it was previously evidenced a resistance to TM in cirrhotic patients. Methods: Citrated blood samples of 42patients with confirmed cirrhosis classified according to the Child score (A,B,C), free of familial history of thromboembolism or thrombophilia and not treated by anticoagulant were analyzed. TG was triggered by 5 pM of TF in the presence/absence of thrombomodulin (4 µm), and 4 µM of phospholipids (Cat Assay, Stago,France). TFa was determined by a home-made assay, free TFPI (fTFPI) by the Asserachrom Free TFPI (Diagnostica Stago, France). Protein C (PC) and S (PS) quantified by Staclot Protein C and S assays (Diagnostica Stago, France). Results were compared to a group of 30 healthy subjects (CT). Results: Main results are summarized in the table. For TG assay, only the Lag-Time (LT) and the Endogenous Thrombin Potential (ETP) were indicated.Table 1.nTFa (pM)fTFPI (ng/mL)Thrombin generationPC (%)PC (%)without TMwith TMRatioLT (min)ETP (nM/min)LT (min)ETP (nM/min)ETP+TM/ ETP-TMCT300.24 ± 0.1114.2 ± 3.52.46 ± 0.241659 ± 2882.59 ± 0.21008 ± 2730.60 ± 0.08126 ± 1482 ± 11A120.49** ± 0.7213.8 ± 5.32.82 ± 0.551338** ± 2803.12 ± 0.64862 ± 2220.66 ± 0.1658.9*** ± 10.954.6*** ± 11.6B192.73 ** ± 5.116.5 ± 6.452.82 ± 0.711349* ± 4252.93 ± 0.6998 ± 2190.73 ** ± 0.1146.4***, ° ± 11.148.7*** ± 17.8C114.23 **, °°° ± 5.7620.3 ± 11.52.61 ± 0.611574 ± 3892.99 ± 0.681216 ± 3000.78 **, ° ± 0.0735.6***, °°° ± 1349.3*** ± 18* p< 0.05; ** p < 0.01 versus CT; ° p < 0.01 °°°; p < 0.001 versus Child A (non-parametric Mann-Whittney test) TFa was significantly (p < °0.01) increased in comparison with CT, and patients with the most severe disease (Child C) have higher levels (p < 0.001) than patients with the lowest Child score (A). In contrast, fTFPI levels were not significantly different from CT, whatever the Child score was. A significant decrease of ETP (without TM) was observed for cirrhotic patients with the lowest Child scores (A and B) in comparison with CT, whereas the lag-time (with and without TM) and ETP with TM were not different from CT. Therefore, the ratios of ETP with TM/ETP without TM increased significantly, indicating a resistance to the anticoagulant activity of TM, in relation to the severity of the disease. This resistance was in part explained by the decrease levels of PC since there was a significant negative correlation (r = - 0.35, p = 0.03) between PC levels and the ratio ETP + TM/ETP - TM. PC levels were also inversely correlated to ETP levels, in the absence (r = - 0.54, p = 0.0006) or presence of TM (r = - 0.53, p = 0.0006). PC levels were also inversely correlated to TFa levels (r = - 0.39, p = 0.01), suggesting that PC decrease could be related to a defective synthesis, but also possibly by a consumption due to the activation of the coagulation cascade by the TF. In contrast, no significant correlation were observed for PS. Conclusion: In addition toaresistance to the anticoagulant activity of the PC pathway, cirrhotic patients with the more severe disease stage (Child C) have high levels of TF activity which is not counterbalanced by TFPI. This could contribute to the higher prevalence of thrombotic disease in these patients. The origin of TF remains to be established, but could come from Kuppfer cells in reaction to the liver injury. These results may have clinical implication for the treatment or prophylaxis of thrombosis in cirrhotic patients. Disclosures Van Dreden: Diagnostica Stago: Employment.

Regulation Of Hematopoietic Stem Cell Trafficking By The Coagulation Pathway

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 456-456
Author(s):  
Shiri Gur Cohen ◽  
Tomer Itkin ◽  
Orit Kollet ◽  
Sagarika Chakrabarty ◽  
Aya Ludin ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Progenitor Cells ◽  
Protein C ◽  
Thrombin Generation ◽  
Activated Protein C ◽  
Coagulation Factors ◽  
Coagulation Cascade ◽  
Hematopoietic Stem

Hematopoeitic stem and progenitor cells (HSPC) dynamically switch between a quiescent, non-motile mode in the bone marrow (BM), to an active state, in which they proliferate, differentiate and egress to the circulation. Injection of the coagulation protease thrombin induced rapid HSPC mobilization to the blood via activation of its major receptor, protease activated receptor 1 (PAR1) on BM hematopoietic and stromal cells. We hypothesized that coagulation factors control stem cells fate in the BM. We examined if thrombin is generated in the murine BM and found by immunohistochemistry prothrombin associated with bone lining osteoblasts in the endosteum region. These cells also highly express osteopontin which induces stem cell quiescence and retention. Cleavage of osteopontin by thrombin or by osteoclast derived cathepsin K induces stem cell mobilization. In addition, a unique structure of multinucleated CD45+ cell clusters in the trabecular-rich area of the murine femoral metaphysis express the cell surface receptor Tissue Factor (TF), a potent initiator of the coagulation cascade leading to thrombin generation. These clusters were found adjacent to multinucleated TRAP (tatrate resistant acid phosphate) positive active osteoclasts. In vitro, we found that immature osteoclasts expressed TF in cell fusion areas, suggesting that osteoclast maturation also activates the coagulation thrombin/PAR1 axis, thus mediating HSPC recruitment to the circulation. Supporting this notion, bleeding which prompts a hemostatic response and thrombin production, is a strong inducer of osteoclasts activation and HSPC mobilization. In addition, injection of bacterial lipopolysaccharides (LPS) is known to activate osteoclasts and induce HSPC mobilization (Kollet et al Nat Med 06). We found that LPS injection upregulated TF expression by CD45+ myeloid cells in the murine BM. LPS treatment provoked massive HSPC mobilization, which was attenuated by PAR1 inhibition. To further address the role of thrombin in stem cell maintenance, we targeted prothrombin in vivo by applying Antisense Oligonucleotides (ASO) knockdown technology, previously shown to induce a dose- and time-dependent up to 90% reduction of prothrombin mRNA levels in the murine liver (Monia et al Blood 2010). Prothrombin depletion altered the BM niche microenvironment by expanding the mesenchymal stem and progenitor (MSPC) population and the long-term repopulating CD34-/ROSlow/LSK HSPC population in the BM. In untreated mice, TF was also expressed by a small MSPC population, suggesting that the bone stomal compartment may also contribute to the regulation of HSPC mobilization upon demand. To further asses the role of thrombin generation in HSPC development, we examined the involvement of the endothelial cell receptor Thrombomodulin (TM) that is pivotal for the anticoagulant pathway which mediates activation of protein C. TM protein is expressed by BM small blood vessels resembling sinusoids and by neighboring MSPC. By immunohistochemistry, we also detected activated protein C on the same blood vessels. A mouse model with a mutation in the TM gene (TMPro/Pro) is characterized by reduced capacity for activated protein C generation which in turn increases thrombin levels in these mice. We found increased circulating hematopoietic stem cells in TMPro/Pro mice, suggesting that chronically increased basal levels of thrombin generation can promote HSC egress. Conversely, short term (5 day) intermittent treatment of mice with low dose thrombin that mainly causes activated protein C formation in vivo, display higher levels of CD34-/ROSlow/LSK and EPCR+LSK stem cells in the BM, indicating additional roles for the anticoagulant pathway in BM stem cell pool maintenance. In summary, our results provide evidence that the activator of the coagulation cascade, TF, and coagulation factors Thrombin and activated protein C are present in the BM and regulate and integrate functions of hematopoietic stem and progenitor cells and BM stromal progenitor cells. Disclosures: Crosby: Isis pharmaceuticals: the ASO for prothrombin was obtained from Isis pharmaceuticals Other. Monia:Isis pharmaceuticals: the ASO for prothrombin was obtained from Isis pharmaceuticals Other.

EXPRESSION IN ONTOGENESIS OF HUMAN BLOOD COAGULATION FACTORS

1987 ◽  
Author(s):  
H J Hassan ◽  
A Leonardi ◽  
C Chelucci ◽  
R Guerriero ◽  
P M Mannucci ◽  
...  
Keyword(s):  
Blood Coagulation ◽  
Protein C ◽  
Antithrombin Iii ◽  
Liver Homogenate ◽  
Coagulation Factor ◽  
Coagulation Factors ◽  
Factor Ix ◽  
Adult Liver ◽  
Blood Coagulation Factors ◽  
Guanidine Isothiocyanate

We have analyzed the expression of several blood coagulation factors (IX, VIII, X, fibrinogen chains) and inhibitors (antithrombin III, protein C) in human embryonic and fetal livers, obtained from legal abortions at 6-11 week post-conception. The age was established by morphologic staging and particularly crown-rump lenght measurement.Total cellular RNA was isolated from partially purified hepatocytes or total liver homogenate using the guanidine isothiocyanate method. Poly(A)+ RNA was selected by oligodT cellulose chromatography. The size and the number of the embryonic and fetal transcripts are equivalent to those observed in adult liver, as evaluated by Northern blot analysis of total or poly(A)+ RNA hybridized to human cDNA probes.The level of coagulation factor transcripts in embryonic and fetal liver was evaluated by dot hybridization of total RNA (0.5-10 ug), as compared to RNA extracted from normal adult liver biopsies. The expression of blood coagulation factors in embryos is generally reduced for all factors, but at a different degree. In 5-11 wk liver, the level of factor IX is 5-10% of that observed in adults, while fibrinogen, protein C, antithrombin III RNA level rises from 25 to 50% and factor X is expressed at a level comparable to that observed in adult liver.We conclude that during these stages of development blood coagulation factors are expressed according to three different time, curves, possibly due to the effect of different types of regulatory mechanisms.

scholarly journals The Role of Coagulation and Complement Factors for Mast Cell Activation in the Pathogenesis of Chronic Spontaneous Urticaria

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1759
Author(s):  
Yuhki Yanase ◽  
Shunsuke Takahagi ◽  
Koichiro Ozawa ◽  
Michihiro Hide
Keyword(s):  
Mast Cells ◽  
Cell Activation ◽  
Coagulation Factors ◽  
Chronic Spontaneous Urticaria ◽  
Mast Cell Activation ◽  
Coagulation Cascade ◽  
Edema Formation ◽  
Complement Components ◽  
Complement Factors

Chronic spontaneous urticaria (CSU) is a common skin disorder characterized by an almost daily recurrence of wheal and flare with itch for more than 6 weeks, in association with the release of stored inflammatory mediators, such as histamine, from skin mast cells and/or peripheral basophils. The involvement of the extrinsic coagulation cascade triggered by tissue factor (TF) and complement factors, such as C3a and C5a, has been implied in the pathogenesis of CSU. However, it has been unclear how the TF-triggered coagulation pathway and complement factors induce the activation of skin mast cells and peripheral basophils in patients with CSU. In this review, we focus on the role of vascular endothelial cells, leukocytes, extrinsic coagulation factors and complement components on TF-induced activation of skin mast cells and peripheral basophils followed by the edema formation clinically recognized as urticaria. These findings suggest that medications targeting activated coagulation factors and/or complement components may represent new and effective treatments for patients with severe and refractory CSU.

Loss of Protein C in Zebrafish Results in Impaired Neutrophil Migration after Tissue Injury

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 22-22
Author(s):  
Chia-Jui Ku ◽  
Steven Grzegorski ◽  
Jordan A. Shavit
Keyword(s):  
Genome Editing ◽  
Protein C ◽  
Tissue Injury ◽  
Neutrophil Migration ◽  
Neutrophil Recruitment ◽  
Coagulation Cascade ◽  
Consumptive Coagulopathy ◽  
Neonatal Lethality ◽  
Independent Functions

Hemostasis is a natural protective process that developed to retain a circulating blood system, conferred by a complicated yet sophisticated balance of factors. Disturbances of this network result in thrombosis or hemorrhage. Among many well-characterized coagulation factors, protein C (PC) exhibits multifunctional roles including anticoagulant, cytoprotective, and anti-inflammatory activities. The importance of PC has been demonstrated not only by the increased risk of venous thrombosis in individuals with heterozygous deficiency, but also the observed neonatal lethality in patients. Knockout mice exhibit similar neonatal lethality, which has made it difficult to further study complete deficiency. The zebrafish is a vertebrate organism that is characterized by a powerful genetic system, prolific breeding, rapid and transparent development, and a well described and highly conserved coagulation cascade. Here we utilize genome editing to generate a null allele of the PC gene (proc) in zebrafish and discover that its loss not only impairs hemostatic balance, but also affects neutrophil recruitment to sites of tissue injury. Through examination of publicly available zebrafish genome sequence, we determined that the proc locus is duplicated in tandem, resulting in two closely adjacent copies with nearly identical sequences. We used CRISPR/Cas9 with two single guide RNAs flanking the entire locus to produce a 17.3 kilobase deletion that knocks out both copies of proc to produce a complete null mutation, verified by sequencing and quantitative PCR. proc-/- mutants survived well into adulthood, with ~50% lethality by seven months of age. The embryonic survival and accessibility enabled us to perform intravital microscopy to evaluate the hemostatic effects of PC deficiency. We used laser-induced endothelial injury on the posterior cardinal vein (PCV) at 3 days post fertilization (dpf), which typically results in rapid formation of an occlusive fibrin-rich thrombus. proc-/- mutants had an average time to occlusion of 60 seconds versus 13 seconds in controls (p &lt; 0.0001), consistent with a consumptive coagulopathy, as previously seen in antithrombin III (at3) mutants. A transgenic background with fluorescently labeled fibrinogen showed that more than 95% of proc-/- mutants had spontaneous thrombi in the PCV, which was not present in controls. To assess the role of PC in inflammation, we used two different injury strategies, non-vascular tail transection and chemical treatment (copper sulfate), on 3 dpf zebrafish larvae. Staining for neutrophil granules revealed homing to the site of injury within 60-75 minutes. In proc-/- mutants we found an average 50% reduction in the number of neutrophils recruited to the site of injury yet counts in the caudal hematopoietic tissue (the site of larval hematopoiesis) were unchanged. Since protein S (PS) is a cofactor for PC anticoagulant function, we hypothesized that the consumptive coagulopathy, but not the neutrophil recruitment, would be PS-dependent. We used genome editing to disrupt the PS gene (pros1) and found that loss of PS also results in a mild consumptive coagulopathy, but spontaneous thrombus formation was less common in the PCV (25%) and was often in the heart instead (80%). Neutrophil recruitment was unaffected in pros1 mutants, and evaluation of double proc/pros1 mutants revealed no synergy in any of the phenotypes. In conclusion, PC and PS deficiency in zebrafish show some similarity to our previously reported model of AT3 deficiency, but the effects are less potent, allowing robust survival that enables in vivo analyses. Our data suggest that the thrombotic phenotypes of PC and PS deficiency are not identical, and display tissue-specific phenotypes. We also found evidence for PS-independent functions of PC in neutrophil migration. We speculate this is due to the role that PC plays in inflammation and signaling but cannot exclude a role in neutrophil extracellular trap (NET) formation. This model of complete proc-/- deficiency in an accessible organism will facilitate further in vivo study of PS-dependent and independent functions of PC, as well as interplay between the two factors. Disclosures Shavit: Bayer: Consultancy; Taked: Consultancy.

scholarly journals Vitamin K-Dependent Coagulation Factors That May be Responsible for Both Bleeding and Thrombosis (FII, FVII, and FIX)

2018 ◽  
Vol 24 (9_suppl) ◽  
pp. 42S-47S ◽  
Author(s):  
Antonio Girolami ◽  
Silvia Ferrari ◽  
Elisabetta Cosi ◽  
Claudia Santarossa ◽  
Maria Luigia Randi
Keyword(s):  
Venous Thrombosis ◽  
Vitamin K ◽  
Protein C ◽  
Protein S ◽  
Coagulation Factors ◽  
Bleeding Tendency ◽  
Clotting Factors ◽  
Protein Z ◽  
Clinical Observations

Vitamin K-dependent clotting factors are commonly divided into prohemorrhagic (FII, FVII, FIX, and FX) and antithrombotic (protein C and protein S). Furthermore, another protein (protein Z) does not seem strictly correlated with blood clotting. As a consequence of this assumption, vitamin K-dependent defects were considered as hemorrhagic or thrombotic disorders. Recent clinical observations, and especially, recent advances in molecular biology investigations, have demonstrated that this was incorrect. In 2009, it was demonstrated that the mutation Arg338Leu in exon 8 of FIX was associated with the appearance of a thrombophilic state and venous thrombosis. The defect was characterized by a 10-fold increased activity in FIX activity, while FIX antigen was only slightly increased (FIX Padua). On the other hand, it was noted on clinical grounds that the thrombosis, mainly venous, was present in about 2% to 3% of patients with FVII deficiency. It was subsequently demonstrated that 2 mutations in FVII, namely, Arg304Gln and Ala294Val, were particularly affected. Both these mutations are type 2 defects, namely, they show low activity but normal or near-normal FVII antigen. More recently, in 2011-2012, it was noted that prothrombin defects due to mutations of Arg596 to Leu, Gln, or Trp in exon 15 cause the appearance of a dysprothrombinemia that shows no bleeding tendency but instead a prothrombotic state with venous thrombosis. On the contrary, no abnormality of protein C or protein S has been shown to be associated with bleeding rather than with thrombosis. These studies have considerably widened the spectrum and significance of blood coagulation studies.

Exosite-dependent regulation of factor VIIIa by activated protein C

Blood ◽  
2003 ◽  
Vol 101 (12) ◽  
pp. 4802-4807 ◽  
Author(s):  
Chandrashekhara Manithody ◽  
Philip J. Fay ◽  
Alireza R. Rezaie
Keyword(s):  
Protein C ◽  
Time Course ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Limited Proteolysis ◽  
Activated Protein C ◽  
Coagulation Cascade ◽  
Factor Va ◽  
Factor Viiia

AbstractActivated protein C (APC) is a natural anticoagulant serine protease in plasma that down-regulates the coagulation cascade by degrading cofactors Va and VIIIa by limited proteolysis. Recent results have indicated that basic residues of 2 surface loops known as the 39-loop (Lys37-Lys39) and the Ca2+-binding 70-80–loop (Arg74 and Arg75) are critical for the anticoagulant function of APC. Kinetics of factor Va degradation by APC mutants in purified systems have demonstrated that basic residues of these loops are involved in determination of the cleavage specificity of the Arg506 scissile bond on the A2 domain of factor Va. In this study, we characterized the properties of the same exosite mutants of APC with respect to their ability to interact with factor VIIIa. Time course of the factor VIIIa degradation by APC mutants suggested that the same basic residues of APC are also critical for recognition and degradation of factor VIIIa. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) of the factor VIIIa cleavage reactions revealed that these residues are involved in determination of the specificity of both A1 and A2 subunits in factor VIIIa, thus facilitating the cleavages of both Arg336 and Arg562 scissile bonds in the cofactor.

scholarly journals A Thrombomodulin Promoter Gene Polymorphism, rs2239562, Influences Both Susceptibility to and Outcome of Sepsis

2022 ◽  
Vol 8 ◽  
Author(s):  
Eizo Watanabe ◽  
Osamu Takasu ◽  
Youichi Teratake ◽  
Teruo Sakamoto ◽  
Toshiaki Ikeda ◽  
...  
Keyword(s):  
Severe Sepsis ◽  
Protein C ◽  
Validation Cohort ◽  
University Hospital ◽  
Coagulation Cascade ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
Functional Polymorphisms ◽  
Promoter Gene ◽  
Control Study

Objective: Disseminated intravascular coagulation plays a key role in the pathophysiology of sepsis. Thrombomodulin is essential in the protein C system of coagulation cascade, and functional polymorphisms influence the human thrombomodulin gene (THBD). Therefore, we conducted a multicenter study to evaluate the influence of such polymorphisms on the pathophysiology of sepsis.Methods: A collaborative case-control study in the intensive care unit (ICU) of each of five tertiary emergency centers. The study included 259 patients (of whom 125 displayed severe sepsis), who were admitted to the ICU of Chiba University Hospital, Chiba, Japan between October 2001 and September 2008 (discovery cohort) and 793 patients (of whom 271 patients displayed severe sepsis), who were admitted to the five ICUs between October 2008 and September 2012 (multicenter validation cohort). To assess the susceptibility to severe sepsis, we further selected 222 critically ill patients from the validation cohort matched for age, gender, morbidity, and severity with the patients with severe sepsis, but without any evidence of sepsis.Results: We examined whether the eight THBD single nucleotide polymorphisms (SNPs) were associated with susceptibility to and/or mortality of sepsis. Higher mortality on severe sepsis in the discovery and combined cohorts was significantly associated with the CC genotype in a THBD promoter SNP (−1920*C/G; rs2239562) [odds ratio [OR] 2.709 (1.067–6.877), P = 0.033 and OR 1.768 (1.060–2.949), P = 0.028]. Furthermore, rs2239562 SNP was associated with susceptibility to severe sepsis [OR 1.593 (1.086–2.338), P = 0.017].Conclusions: The data demonstrate that rs2239562, the THBD promoter SNP influences both the outcome and susceptibility to severe sepsis.

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