No abstract available.
Carboxypeptidase U

BACKGROUND: Thrombin/thrombomodulin complex activates thrombin activable fibrinolysis inhibitor (TAFI) to active TAFI (TAFIa), which in turn catalyzes the hydrolysis of C-terminal lysine residues of partially degraded fibrin. The fibrin that is partially degraded by TAFIa is not degraded by plasmin. Thus, TAFI inhibits fibrinolysis. An increase in plasma TAFI level is suggested to be associated with thrombotic disorders. In this study, we measured TAFI levels and investigated the distribution of C+1542G polymorphism in Korean patients with ischemic stoke. And, we intended to investigated the role of TAFI in the occurrence of ischemic stroke. METHODS: We enrolled 44 patients who had experienced ischemic stroke episodes more than 6 month ago and had not been treated with oral anticoagulant. We also tested 44 age and sex-matched healthy controls. TAFI antigen levels were measured by an enzyme-linked immunosorbent assay (VisulizeTM TAFI antigen kit; Affinity Biologicals Inc., Ancaster, Canada) and TAFI activity levels were measured by a chromogenic assay (Actichrome TAFI activity kit ; American diagnostica Inc., CT, USA). Genotyping of C+1542G polymorphism was performed by an allele-specific polymerase chain reaction. RESULTS: The range of TAFI antigen was 2.4-12.7microgram/mL (mean+/-2SD) and that of TAFI activity was 4.9-17.9microgram/mL (mean+/-2SD) in healthy controls. TAFI antigen level was not correlated with TAFI activity. TAFI activity was the highest in CC polymorphism and the lowest in GG polymorphism (P= 0.03). The levels of TAFI antigen and activity were lower in the patients with ischemic stroke than in healty controls, but the difference was not statistically significant. There was no difference in the distribution of C+1542G polymorphism between the patients with ischemic stroke and healthy persons. CONCLUSIONS: In this study, TAFI antigen and activity were not significantly associated with the occurrence of ischemic stoke in Korean. And, TAFI may not be a risk factor for ischemic stroke in the Korean population.
Carboxypeptidase U ; Enzyme-Linked Immunosorbent Assay ; Fibrin ; Fibrinolysin ; Fibrinolysis* ; Humans ; Hydrolysis ; Lysine ; Plasma ; Polymerase Chain Reaction ; Risk Factors ; Stroke* ; Thrombin*

BACKGROUND: In sepsis, large scale inflammatory responses can cause extensive collateral damage to the vasculature, because both coagulation and fibrinolysis are activated unevenly. Thrombin-activatable fibrinolysis inhibitor (TAFI) plays a role in modulating fibrinolysis. Since TAFI can be activated by both thrombin and plasmin, it is thought to be affected in sepsis. Hence, activated and inactivated TAFI (TAFIa/ai) may be used to monitor changes in sepsis. METHODS: TAFIa/ai-specific in-house ELISA can detect only the TAFIa/ai form, because the ELISA capture agent is potato tuber carboxypeptidase inhibitor (PTCI), which has selective affinity towards only the TAFIa and TAFIai isoforms. TAFIa/ai levels in plasma from 25 patients with sepsis and 19 healthy volunteers were quantitated with the in-house ELISA. RESULTS: We observed increased TAFIa/ai levels in samples from patients with sepsis (48.7+/-9.3 ng/mL) than in samples from healthy individuals (10.5+/-5.9 ng/mL). In contrast, no difference in total TAFI concentration was obtained between sepsis patients and healthy controls. The results suggest that TAFI zymogen was activated and that TAFIa/ai accumulated in sepsis. CONCLUSION: The detection of TAFIa/ai in plasma could provide a useful and simple diagnostic tool for sepsis. Uneven activation of both coagulation and fibrinolysis in sepsis could be caused by the activation of TAFI zymogen and elevation of TAFIa/ai. TAFIa/ai could be a novel marker to monitor sepsis and other blood-related disturbances.
Carboxypeptidase U ; Enzyme-Linked Immunosorbent Assay ; Fibrinolysin ; Fibrinolysis ; Humans ; Organothiophosphorus Compounds ; Plasma ; Protein Isoforms ; Sepsis ; Solanum tuberosum ; Thrombin

BACKGROUND AND PURPOSE: Thrombolytics-induced recanalization fails in a significant portion of patients with ischemic stroke, which is partly due to the resistance of clots to lysis by thrombolytic agents. The pretreatment level of endogenous fibrinolysis inhibitors may affect such thrombolysis failure. METHODS: We studied 43 stroke patients whose arterial recanalization had been evaluated by angiography, and whose blood had been obtained prior to the administration of thrombolytic agents. Plasma samples from 34 healthy volunteers were used as normal controls. Plasminogen activator inhibitor type 1 (PAI-1) and thrombin-activatable fibrinolysis inhibitor (TAFI) levels were quantified using an enzyme-linked immunosorbent assay. RESULTS: Arteries were recanalized [Thrombolysis in Myocardial Infarction (TIMI) grade 2 or 3] in 30 patients, but not (TIMI grade 0 or 1) in the other 13. The plasma PAI-1 level was significantly higher in patients without recanalization (nonrecanalization) than in those with recanalization and in normal controls. The TAFI levels did not differ among the groups. CONCLUSIONS: The pretreatment PAI-1 levels are increased in acute stroke patients with thrombolysis failure.
Angiography ; Arteries ; Carboxypeptidase U ; Enzyme-Linked Immunosorbent Assay ; Fibrinolysis* ; Fibrinolytic Agents ; Healthy Volunteers ; Humans ; Myocardial Infarction ; Plasma* ; Plasminogen Activator Inhibitor 1 ; Plasminogen Activators ; Stroke*

This study was aimed to explore the change of single nucleotide polymorphism (SNP) of thrombin-activatable fibrinolysis inhibitor (TAFI) and its correlation of 2 sites (505a/g, 1040c/t) in its gene-coding region with venous thromboembolism (VTE). The genotype distribution of TAFI in 80 patients with VTE and 80 normal controls was detected by allele-specific PCR. The results showed that the distribution of each genotype of 505a/g polymorphism was not significantly different between the VTE and control groups (P > 0.05). However, t allele frequency of 1040c/t in VTE group decreased significantly as compared with the control group (40% vs 53.75%, P < 0.05), mainly due to the decrease of the proportion of tt homozygous in VTE group. It is concluded that obvious relationship is found between the polymorphism of 1040c/t in TAFI gene and VTE patients. t allele genotype may paly a protective role in VTE. The polymorphism of TAFI 505a/g may be not associated with VTE.
Adult ; Aged ; Aged, 80 and over ; Carboxypeptidase B2 ; genetics ; Case-Control Studies ; Female ; Gene Frequency ; Genotype ; Humans ; Male ; Middle Aged ; Polymorphism, Single Nucleotide ; Venous Thromboembolism ; genetics

OBJECTIVETo explore the clinical significance of fibrinolysis inhibitors including thrombin activatable fibrinolysis inhibitor(TAFI), plasminogen activator inhibitor (PAI) and alpha2-plasmin inhibitor (alpha2-PI) in acute leukemia (AL).

METHODSPAI-1 antigen and TAFI antigen were investigated by enzyme-linked immunosorbent assay and PAI activity, alpha2-PI activity, TAFI activity by chromatography substrate assay in 117 AL patients and 50 normal controls.

RESULTS1) alpha2-PI activities in AL patients were reduced, especially in ALL patients [(96.8 +/- 21.2)%]; 2) PAI-1 antigens in AML patients [(37.8 +/- 9.2) microg/L] were significantly higher than that in normal controls [(33.8 +/- 4.9) microg/L]; 3) PAI-1 antigens in APL [(37.8 +/- 9.0) microg/L] and AML-M5 patients [(39.9 +/- 11.6) microg/L] were higher and TAFI activities in APL patients [(13.3 +/- 4.8) mg/L] were lower than that in normal controls [(16.9 +/- 2.6) mg/L]; 4) PAI-1 antigens of relapsed/refractory patients (39.6 +/- 11.6) microg/L) were significantly elevated; 5) TAFI activities in bleeding patients [(13.2 +/- 5.3) mg/L] were significantly lower than that in normal control as well as non-bleeding patients (17.0 +/- 4.6) mg/L); 6) The severity of bleeding was negatively correlated with TAFI activity (r = - 0.276, P <0.05).

CONCLUSIONSHyperfibrinolysis caused partially by decrease of alpha2-PI and TAFI activity takes part in the pathogenesis of bleeding in AL.

Acute Disease ; Adolescent ; Adult ; Aged ; Carboxypeptidase B2 ; blood ; Child ; Female ; Humans ; Leukemia ; blood ; Male ; Middle Aged ; Plasminogen Activator Inhibitor 1 ; blood ; Young Adult

OBJECTIVETo investigate the association of thrombin activatable fibrinolysis inhibitor (TAFI) and its encoding gene CPB2 polymorphism in patients with coronary heart disease (CHD).

METHODSThe CPB2 gene polymorphisms of Thr325Ile and Thr147Ala were analyzed with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in patients of acute myocardial infarction (n=100), acute angina pectoris (n=110) and a control group (n=190). The antigen (Ag) and activity (Act) of the TAFI were determined by sandwich enzyme link immunosorbent assay specific for human TAFI and chromogenic assay for activated human TAFI in plasma, respectively. The relationship between Thr325Ile and Thr147Ala gene polymorphism and TAFI Ag and Act were also analyzed.

RESULTSPlasma TAFI Act and TAFI Ag in acute myocardial infarction group and acute angina pectoris group (CHD patients group) were both significantly higher than those of the control group. The genotype frequencies of Thr325Ile (C1040T) and Thr147Ala (G505A) were as the following: C1040C (Thr325Thr) 67 (31.9%) and 64 (33.6%); C1040T (Thr325Ile) 109 (51.9%) and 92 (48.4%); T1040T (Ile325Ile) 34 (16.2%) and 34(17.8%); G505G (Ala147 Ala) 75 (35.7%) and 72 (37.8%); G505A(Thr147Ala) 112 (53.3%) and 96 (50.5%); A505A(Thr147Thr)23 (10.9%) and 22 (11.7%), in the CHD patients and control respectively. Chi-square analysis showed no significant difference in the Thr325Ile and Thr147Ala polymorphism distributions (P > 0.05). In addition, at the 325 position, the TAFI antigen of the Thr325Thr was higher than that of the other genotypes (Thr325Ile and Ile325Ile, P < 0.05). There was no statistical significance between the TAFI antigen of the Thr325Ile and Ile325Ile (P > 0.05). No significant correlation was found between the TAFI Act and the Thr325Ile polymorphism. At the position 147, significant correlation between the polymorphism of the Thr147Ala and TAFI Ag and Act was not found.

CONCLUSIONTAFI plays an important role in anti-fibrinolysis. It might be a risk factor for acute myocardial infarction and acute angina pectoris. The Thr325Ile polymorphism had obvious effect on TAFI antigen levels, but the Thr325Ile and Thr147Ala polymorphism had no association with coronary heart disease.

Amino Acid Substitution ; Carboxypeptidase B2 ; blood ; genetics ; Coronary Disease ; genetics ; Female ; Fibrinolysis ; genetics ; Gene Frequency ; Genotype ; Humans ; Male ; Middle Aged ; Mutation ; Polymorphism, Genetic ; Polymorphism, Single Nucleotide

OBJECTIVETo investigate the antithrombotic mechanisms of holothurian glycosaminoglycan (GAG) extracted from sea cucumber.

METHODSHuman endothelial cell line EA. hy926 cells were treated with 10 mg/L GAG or 10U/mL unfractionated heparin (UFH) by short-term (15 min - 2 h) and longer-time incubation (6 h - 48 h). Different doses of GAG were used to stimulate EA. hy926. Released free tissue factor pathway inhibitor(TFPI) was determined by ELISA assay. TFPI expression was investigated by immunofluorescent method and TFPI mRNA level by real-time PCR. In a 96-wells microtitre plate, pooled normal plasma containing different concentrations of GAG was allowed to clot by addition of thrombin and calcium chloride, fibrinolysis was induced by addition of t-PA. TRR (TAFI-related retardation of clot lysis) was used to assess thrombin-activatable fibrinolysis inhibitor(TAFI) functional activity.

RESULTSGAG increased TFPI synthesis, expression and secretion in a dose- and time dependent manner. GAG at low concentrations could lengthen while at intermediate concentrations could shorten clot lysis times significantly as compared to control values. TRR was dose-dependently decreased on addition of GAG.

CONCLUSIONSGAG increases TFPI synthesis, expression and secretion of endothelial cells. GAG at intermediate concentrations significantly affects clot stability of a developing clot by means of diminishing TAFI activation.

Animals ; Carboxypeptidase B2 ; antagonists & inhibitors ; Cell Line ; Dose-Response Relationship, Drug ; Endothelial Cells ; drug effects ; metabolism ; Glycosaminoglycans ; pharmacology ; Heparin ; pharmacology ; Holothuria ; Humans ; Lipoproteins ; biosynthesis ; genetics ; RNA, Messenger ; genetics ; Tissue Extracts ; pharmacology

AIMTo study the effect of recombinant hirudin (rH) on tPA-induced fibrinolysis and the possible mechanism of its action.

METHODSThe effect of rH on thrombin-fibrin complex (Th-Fn) was detected by 99mTc labeled rH. In the in vitro clot lysis, tPA as plasminogen activator, and recalcified plasma as plasminogen resource were used to study the influence of rH on fibrinolysis by detecting TAFIa, D-Dimer and FXIII.

RESULTSIn a canine model of femoral artery thrombosis, a clear radioactivity strip was imaged in 30 - 60 min on a part image, and the femoral vein thrombosis developed at 30 min. rH efficiently inhibited clot regeneration. Addition of TM could inhibit clot lysis obviously, and CPI could shorten the delay of clot lysis which due to TAFIa. There was a dose-dependent relationship with TM concentration and TAFI activation. FXIII activation was inhibited by low concentration of rH ( < or = 0.2 u x mL(-1)), and the level of fibrinolysis product, D-Dimer, increased.

CONCLUSIONrH could inhibit the thrombin binding to fibrin. rH inhibited the activation of TAFI and FXIII by combining with thrombin which resulted in enhancement of thrombolysis.

Animals ; Blood Coagulation ; drug effects ; Carboxypeptidase B2 ; metabolism ; Carboxypeptidases ; antagonists & inhibitors ; Dogs ; Factor XIII ; metabolism ; Femoral Artery ; Femoral Vein ; Fibrinolysis ; drug effects ; Fibrinolytic Agents ; pharmacology ; Hirudins ; genetics ; pharmacology ; Male ; Plant Proteins ; pharmacology ; Protease Inhibitors ; Recombinant Proteins ; pharmacology ; Thrombomodulin ; metabolism ; Thrombosis ; metabolism ; Venous Thrombosis ; metabolism