Tissue factor pathway inhibitor dose-dependently inhibits coagulation activation without influencing the fibrinolytic and cytokine response during human endotoxemia

Inhibition of the tissue factor pathway has been shown to attenuate the activation of coagulation and to prevent death in a gram-negative bacteremia primate model of sepsis. It has been suggested that tissue factor influences inflammatory cascades other than the coagulation system. The authors sought to determine the effects of 2 different doses of recombinant tissue factor pathway inhibitor (TFPI) on endotoxin-induced coagulant, fibrinolytic, and cytokine responses in healthy humans. Two groups, each consisting of 8 healthy men, were studied in a double-blind, randomized, placebo-controlled crossover study. Subjects were studied on 2 different occasions. They received a bolus intravenous injection of 4 ng/kg endotoxin, which was followed by a 6-hour continuous infusion of TFPI or placebo. Eight subjects received 0.05 mg/kg per hour TFPI after a bolus of 0.0125 mg/kg (low-dose group), and 8 subjects received 0.2 mg/kg per hour after a bolus of 0.05 mg/kg (high-dose group). Endotoxin injection induced the activation of coagulation, the activation and subsequent inhibition of fibrinolysis, and the release of proinflammatory and antiinflammatory cytokines. TFPI infusion induced a dose-dependent attenuation of thrombin generation, as measured by plasma F1 + 2 and thrombin-antithrombin complexes, with a complete blockade of coagulation activation after high-dose TFPI. Endotoxin-induced changes in the fibrinolytic system and cytokine levels were not altered by either low-dose or high-dose TFPI. The authors concluded that TFPI effectively and dose-dependently attenuates the endotoxin-induced coagulation activation in humans without influencing the fibrinolytic and cytokine response. (Blood. 2000;95:1124-1129)     

纤维支气管镜活检病变组织标本和痰标本Survivin基因的检测对肺癌的诊断价值

目的明确纤维支气管镜(以下简称纤支镜)活检病变组织和痰标本中SurvivinmRNA的检测在肺癌诊断中的意义。方法应用逆转录聚合酶链反应(RT PCR)法检测41例肺癌手术标本癌组织、癌旁组织和9例良性肺疾病病变组织手术标本,80例肺癌和30例良性肺疾病纤支镜活检病变组织标本及所有(160例)患者痰标本SurvivinmRNA表达情况,并与病理组织学、刷检细胞学和痰细胞学检查结果比较。结果肺癌手术切除标本癌组织SurvivinmRNA的阳性率为70.7%(29/41),高于癌旁组织[17.1%(7/41)]和良性肺疾病组织(1/9),差异有统计学意义(χ2值分别为23.97和10.93,P均<0.05),而癌旁组织与肺良性疾病组织相比,差异无统计学意义(χ2=0.20,P>0.05);纤支镜活检肺癌组织标本SurvivinmRNA的阳性率为63.8%(51/80),高于良性肺疾病的13.3%(4/30,χ2值为22.18,P<0.05);肺癌患者癌组织SurvivinmRNA表达与否及表达水平与患者年龄、性别及肿瘤的病理分型、分级、部位及转移情况均无明显相关性(P均>0.05)。肺癌患者痰标本SurvivinmRNA的阳性率是59.5%(72/121),癌细胞的检出率是47.1%(57/121);痰Survivin mRNA检测联合痰细胞学检查诊断肺癌的敏感性为80.2%(97/121),高于单独痰细胞学及单独痰SurvivinmRNA检测的敏感性(P均<0.05)。手术标本、纤支镜活检标     

Expression of tissue factor in pancreatic adenocarcinoma is associated with activation of coagulation

AIM: To study expression of tissue factor (TF) in pancreatic cancer and its role in the development of thromboembolism. METHODS: TF expression was studied in eight human pancreatic carcinoma cell lines by Northern blot and indirect immunofluorescence. Expression of alternatively spliced TF (asTF) was assessed by RT-PCR. In addition, TF expression was determined by immunofluorescence in pancreatic tissues of 19 patients with pancreatic adenocarcinoma (PCa), 9 patients with chronic pancreatitis (CP) and 20 normal controls. Plasma samples (30 PCa-patients, 13 CP-patients and 20 controls) were investigated for soluble TF levels and coagulation activation markers [thrombin-antithrombin III complex (TAT), prothrombin fragment 1 2 (F1 2)]. RESULTS: All pancreatic carcinoma cell lines expressed TF (8/8) and most of them expressed asTF (6/8). TF expression at the protein level did not correlate with the differentiation of the carcinoma cell line. All but two pancreatic cancer tissue samples stained positive for TF (17/19). In all samples of CP weak staining was restricted to pancreatic duct cells, whereas only a few subendothelial cells were positive in 9/20 of normal controls. TF and TAT levels in PCa patients were significantly elevated compared to controls whereas elevated F1 2 levels did not reach statistical significance compared to controls. In CP patients TAT and F1 2 levels proved to be significantly elevated compared to controls, although TAT elevation was less pronounced than in PCa patients. CONCLUSION: We conclude that in addition to the upregulated expression of TF on the cell membrane, soluble TF might contribute to activation of the coagulation system in pancreatic cancer.     

Platelet activation at the onset of human endotoxemia is undetectable in vivo

Infection induces platelet activation and consumption, which leads to thrombocytopenia, enhances microvascular thrombosis, impairs microcirculation and eventually triggers disseminated intravascular coagulation (DIC). It is well characterized that endotoxemia results in a pro-inflammatory and pro-coagulatory state, which favors platelet activation. However the early, direct effects of endotoxemia on platelets have not been investigated so far. Therefore we aimed to determine the early effects of the endotoxin lipopolysaccharide (LPS) on platelet function in vivo. In a human endotoxemia model, 15 healthy volunteers were stimulated with LPS (2 ng/kg). Blood was drawn before, 10, 30 and 60 min after LPS challenge and platelet activation analyzed by flow cytometry (GPIIb/IIIa activation, surface CD62P and CD40L, intraplatelet reactive oxygen formation and platelet–leukocyte aggregates) and ELISA (sCD40L, sCD62P and CXCL4). In parallel, blood samples and platelets were spiked with LPS (50 pg/ml) in vitro and monitored over 60 min for the same platelet activation markers.

In vitro platelet stimulation with LPS activated platelets independent of the presence of leukocytes and enhanced their adhesion to endothelial cells. In contrast, in vivo no increase in GPIIb/IIIa activation or surface expression of CD62P was observed. However, endotoxemia resulted in a significant drop in platelet count and elevated the plasma CXCL4 levels already 10 min after the LPS challenge.

These data indicate that LPS rapidly activates platelets, leading to α-granule release and endothelial adhesion. This might explain the drop in platelet count observed at the onset of endotoxemia.     

Expression of tissue factor in pancreatic adenocarcinoma is associated with activation of coagulation

AIM: To study expression of tissue factor (TF) in pancreatic cancer and its role in the development of thromboembolism. METHODS: TF expression was studied in eight human pancreatic carcinoma cell lines by Northern blot and indirect immunofluorescence. Expression of alternatively spliced TF (asTF) was assessed by RTPCR. In addition, TF expression was determined by immunofluorescence in pancreatic tissues of 19 patients with pancreatic adenocarcinoma (Pca), 9 patients with chronic pancreatitis (CP) and 20 normal controls. Plasma samples (30 Pca-patients, 13 CP-patients and 20 controls) were investigated for soluble TF levels and coagulation activation markers [thrombin-antithrombin Ⅲ complex (TAT), prothrombin fragment 1 + 2 (F1 + 2)]. RESULTS: All pancreatic carcinoma cell lines expressed TF (8/8) and most of them expressed asTF (6/8). TF expression at the protein level did not correlate with the differentiation of the carcinoma cell line. All but two pancreatic cancer tissue samples stained positive for TF (17/19). In all samples of CP weak staining was restricted to pancreatic duct cells, whereas only a few subendothelial cells were positive in 9/20 of normal controls. TF and TAT levels in Pca patients were significantly elevated compared to controls whereas elevated F1 + 2 levels did not reach statistical significance compared to controls. In CP patients TAT and F1 + 2 levels proved to be significantly elevated compared to controls, although TAT elevation was less pronounced than in Pca patients. CONCLUSION: We conclude that in addition to the upregulated expression of TF on the cell membrane, soluble TF might contribute to activation of the coagulation system in pancreatic cancer.     

Induction of microparticle- and cell-associated intravascular tissue factor in human endotoxemia

The precise role of intravascular tissue factor (TF) remains poorly defined, due to the limited availability of assays capable of measuring circulating TF procoagulant activity (PCA). As a model of inflammation-associated intravascular thrombin generation, we studied 18 volunteers receiving an infusion of endotoxin. A novel assay that measures microparticle (MP)-associated TF PCA from a number of cellular sources (but not platelets) demonstrated an 8-fold increase in activity at 3 to 4 hours after endotoxin administration (P <.001), with a return to baseline by 8 hours. TF antigen-positive MPs isolated from plasma were visualized by electron microscopy. Interindividual MP-associated TF response to lipopolysaccharide (LPS) was highly variable. In contrast, a previously described assay that measures total (cell and MP-borne) whole-blood TF PCA demonstrated a more modest increase, with a peak in activity (1.3-fold over baseline; P <.000 01) at 3 to 4 hours, and persistence for more than 24 hours. This surprisingly modest increase in whole-blood TF activity is likely explained by a profound although transient LPS-induced monocytopenia. MP-associated TF PCA was highly correlated with whole-blood TF PCA and total number of circulating MPs, and whole-blood TF PCA was highly correlated with TF mRNA levels.     

The relationship between gender and age with monocyte tissue factor expression

Background In normal healthy individuals, the level of tissue factor (TF) expression on monocytes is low. However, studies have shown that patients with cardiovascular disease (CVD) have elevated levels of TF. As the risk of CVD increases with age and is more prominent in the male population, it is postulated that TF expression may be positively correlated with these factors. However, very few studies have examined the relationship between age and gender on TF expression. Methods This study evaluated the influence of age and gender on TF expression using data obtained from female (n = 44) and male (n = 27) subjects. We also examined the influence of BMI and total fat intake on TF expression in the same subjects. Results The results of our study found no significant difference in TF expression between the male and female subgroups. No correlation was found between TF and age, BMI or total fat intake in the male or female groupings. Conclusion It may be postulated that the risk of CVD development in such populations may not be due to increases in TF expression with increasing age or gender differences.     

Relative messenger RNA expression profiling of collagenases and aggrecanases in human articular chondrocytes in vivo and in vitro

OBJECTIVE: Osteoarthritic (OA) cartilage destruction depends on collagen- and aggrecan-degrading proteases such as collagenases (MMP-1 and MMP-13), stromelysin (MMP-3), MMP-14, as well as the so-called aggrecanases (ADAM-TS4 and ADAM-TS5). In this study, we tried to clarify whether these proteases are expressed in vivo in human normal and OA cartilage (and whether they are up-regulated or down-regulated during the disease process) and in interleukin-1beta (IL-1beta)-stimulated chondrocytes in vitro. METHODS: Quantitative polymerase chain reaction assays were developed and performed on RNA isolated directly from normal and degenerative cartilage tissue as well as from primary human articular chondrocytes cultured with and without IL-1beta. RESULTS: In vivo, MMP-1 was detectable only at very low levels in any condition. MMP-13 expression was low in normal and early degenerative cartilage but was strongly up-regulated in late-stage OA specimens. MMP-1 and MMP-13 were expressed much higher in vitro than in vivo and were up-regulated by IL-1beta. Among all proteases, MMP-3 was by far the most strongly expressed, although it was strongly down-regulated in late-stage OA specimens. Expression of MMP-3 was higher in vitro than in vivo and was up-regulated by IL-1beta. ADAM-TS5 and MMP-14 were expressed in all sample groups. Expression of ADAM-TS4 was very low in vivo and was induced in vitro after stimulation by IL-1beta. CONCLUSION: Our expression data clearly support MMP-13 as the major collagenase in OA cartilage. The most strongly expressed aggrecanase was ADAM-TS5. ADAM-TS4 was expressed only at a very low level in normal cartilage and was only slightly up-regulated in OA cartilage, casting doubt on this enzyme being the relevant aggrecanase of articular cartilage. Results of our study show that expression of many enzymes is significantly different in vitro and in vivo and suggest that IL-1beta stimulation of articular chondrocytes might not be a good model for the matrix catabolism in OA cartilage.     

The kinetics of human granulopoiesis following treatment with granulocyte colony-stimulating factor in vivo.

Cell proliferation in the bone marrow and blood of two patients with metastatic breast cancer who were treated with granulocyte colony-stimulating factor was studied by using [3H]thymidine labeling and autoradiography. Additionally, the fate of neutrophils labeled with 99mTc-hexamethylpropyleneamineoxime was observed following granulocyte colony-stimulating factor infusion. Proliferation increased in all stages of granulopoiesis, but a significant amount of the increased production stemmed from a greater input to the myeloblast compartment. Changes in the myelogram combined with the increased labeling indicated a faster throughput of cells, which resulted in labeled cells appearing in the circulation within 1 day compared to the normal 4 or 5 days. The 99mTc studies demonstrated no sequestration of circulating neutrophils by spleen, lungs, or liver. The half-life of the circulating neutrophils was not significantly changed, and calculations from the flow of labeled cells to the peripheral blood indicated an increase of 3.2 extra amplification divisions during neutrophil development. The dramatic neutrophil response to granulocyte colony-stimulating factor can therefore be accommodated by a relatively modest increase in granulopoietic activity.     

Significance of vascular endothelial growth factor messenger RNA expression in gastric cancer

ＳｉｇｎｉｆｉｃａｎｃｅｏｆｖａｓｃｕｌａｒｅｎｄｏｔｈｅｌｉａｌｇｒｏｗｔｈｆａｃｔｏｒｍｅｓｓｅｎｇｅｒＲＮＡｅｘｐｒｅｓｓｉｏｎｉｎｇａｓｔｒｉｃｃａｎｃｅｒＴＡＯＨｏｕＱｕａｎ１,ＬＩＮＹａｎＺｈｅｎ２ａｎｄＷＡＮＧＲｕｉＮｉａｎ３Ｓｕ...     

Blood coagulation factors in human embryonic-fetal development: preferential expression of the FVII/tissue factor pathway.

The expression of a number of blood coagulation factors (F) (FX, FIX, FVIII, FVII, alpha-, beta-, gamma-fibrinogen chains, protein C, and antithrombin III [AT III]) was analyzed at RNA and protein level in 5- to 10-week-old human embryos and fetuses. FX, FIX, and FVII were also analyzed at protein level. Total and poly(A)+ RNA, extracted from embryonic-fetal (FL) and adult liver (AL), were analyzed by dot and Northern blot hybridization with specific cDNA probes. The results indicate that: (1) the size of the messenger RNAs of these factors is equivalent in FL and AL; (2) in the 5- to 10-week period, their abundance in FL increases from 30% to 50% of the adult level except for FIX (from 2% to 10%) and FX (always 100% of the adult value). Western blot analysis of FIX, FX, and FVII in 5- to 10-week soluble liver proteins and 6- to 8-week plasma showed a low level of FIX versus a higher concentration of both FVII and FX, when compared with corresponding adult values, ie, a liver protein level of 10% versus 100% and a plasma concentration level of 10% versus 40%. Although little is known so far on the activity and the functional role of the clotting factors in early human ontogenic development, these studies suggest an activation of FX via the FVII/tissue factor activity rather than the FIXa/FVIIIa phospholipid complex in human embryonic and early fetal life.     

The effect of platelets in the activation of human blood coagulation factor IX by factor XIa

We report here the effect of activated human platelets on the activation of human factor IX by human factor XIa. Factor IXa formed during activation was determined via its ability to activate bovine factor X. To increase sensitivity, phospholipids and bovine factor VIIIa were present in the assay. The kinetic parameters of the factor IX activation were determined in the presence of 10 mmol/L CaCl2. The Km for factor IX was 0.30 mumol/L and kcat was 2.4 s-1. Activated human platelets inhibited factor IX activation by factor XIa in a dose- dependent manner, whereas unstimulated platelets had no effect. Factor IX activation was inhibited for more than 90% at a platelet concentration of 4 X 10(8)/mL, whereas concentrations of less than 10(6)/mL had no influence. The inhibitory effect could be induced by thrombin, collagen, calcium ionophore A 23187, and adrenalin. The appearance of inhibitory activity could be blocked by the addition of the prostacyclin analogue ZK 36374 at any time during platelet activation. Stirring during platelet activation was not necessary. These results suggest that the inhibition is caused by a release reaction. This was confirmed by centrifugation experiments that showed that the inhibitory activity could be recovered from the supernatant of the activated platelets. The inhibitory activity was destroyed upon boiling and was susceptible to trypsin digestion. Passage of platelet supernatant over ACA 22 showed that the inhibitory activity eluted with an apparent molecular weight of less than 1,200,000 but greater than 669,000. The inhibition of factor XIa was reversible. These data suggest that platelets release an antiprotease of factor XIa that reversibly inhibits factor XIa. Lineweaver-Burk analysis showed that the inhibitor caused both an increase in Km for factor IX and a decrease in kcat of factor IXa formation by factor XIa.     

The single nucleotide polymorphism Ser128Arg in the E-selectin gene is associated with enhanced coagulation during human endotoxemia

The single nucleotide polymorphism (SNP) Ser128Arg in the E-selectin gene is overrepresented in certain patient groups with atherosclerosis or restenosis. We hypothesized and tested whether it may affect cytokine-induced levels of soluble (s) E-selectin, or be associated with proinflammatory or procoagulant properties in a well-standardized inflammation model. Healthy male volunteers (n = 157) received a lipopolysaccharide (LPS) infusion and were genotyped for the S128R SNP, and outcome parameters were measured by enzyme immunoassays and real-time polymerase chain reaction (RT-PCR, Taqman). The S128R SNP had no pronounced effects on basal or inducible sE-selectin levels, or levels of tumor necrosis factor or interleukin-6. However, carriers of the S128R SNP had 20% higher monocyte counts at 24 hours after LPS infusion. Importantly, the S128R allele enhanced thrombin generation by 50% to 80%, as measured by prothrombin fragment F(1+2) (P < .01), and hence fibrin formation (D-dimer) 2-fold (P = .01 to P = .002). However, tissue factor (TF) mRNA levels were not affected. The S128R E-selectin genotype is associated with procoagulant effects in a human model of endotoxin-induced, TF-triggered coagulation. This could contribute to its linkage with various thrombotic cardiovascular disorders.     

人组织因子途径抑制物腺病毒表达系统的构建及体内表达

目的构建携载人组织因子途径抑制物(tissuefactorpathwayinhibitor,TFPI)基因的重组腺病毒载体,为基因治疗提供实验基础。方法利用基因重组技术,将人TFPI基因连接到穿梭质粒pDC316中,然后将腺病毒骨架质粒pBHGlox△E1,3Cre以及重组穿梭质粒pDC316-TFPI共转染293细胞,并在其中发生Cre重组酶介导的位点,特异性重组及腺病毒包装,扩增后进行滴度测定。将包装成功的携带人TFPI基因的重组腺病毒(Ad-TFPI)转染兔颈动脉,并用携带LacZ报告基因的重组腺病毒(Ad-LacZ)作为对照,3d后RT-PCR、ELISA法检测人TFPImRNA、蛋白的表达。结果得到了携带人TFPI基因的重组腺病毒,包装的病毒蚀斑形成单位(plaqueformationunit,PFU)滴度为7.6×1012/L。在Ad-TFPI转染兔颈动脉后3d,RT-PCR法和ELISA法均检测出TFPI表达,Ad-LacZ转染后未测到人TFPI的表达。结论成功构建了人TFPI腺病毒表达载体,为下一步的基因治疗提供了基础。     

Measurement of factor Xa-antithrombin III in plasma: relationship to prothrombin activation in vivo

Summary. The M_r of the complexes formed when factor Xa reacts with antithrombin III (ATIII) in plasma were estimated by gel filtration and SDS-polyacrylamide electrophoresis. The predominant species of factor Xa-ATIII detected after plasma and plasma to which factor Xa had been added were gel filtered on Sephadex G-200 and Sepharose 4B had apparent M_r >200 000, in which factor Xa-ATIII was associated with vitronectin. Addition of factor Xa-ATIII to ATIII-depleted plasma also resulted in the formation of factor Xa-ATIII-vitronectin complexes with M_r > 200 000. Using polyclonal antibodies to human factor Xa-ATIII and ATIII as the capture and detector antibodies, respectively, a sensitive and specific enzyme-linked immunosorbent assay was developed to quantify factor Xa-ATIII in plasma. The relationship between factor Xa-ATIII production and prothrombinase activity in vivo was investigated by quantifying factor Xa-ATIII and prothrombin fragment 1 + 2 endogenous to the plasmas of blood donors and patients with Hodgkin's and non-Hodgkin's lymphoma. Whereas the concentrations of prothrombin fragment 1+2 in the 84 normal plasmas increased with age, those of factor Xa-ATIII (mean ±SD of 34.7 ± 13.8 PM) did not, and no correlation existed between the concentrations of the two parameters in normal plasmas. In contrast, a highly significant correlation between the concentrations of these two parameters was found in the plasmas of the cancer patients which coincidentally also had higher concentrations of both factor Xa-ATIII and prothrombin fragment 1 + 2 than the normal plasmas. Thus, ATIII may differentially influence prothrombinase formation and activity in normal individuals and cancer patients.     

In vivo coagulation activation following infusion of highly purified factor XI concentrate

The use of factor XI concentrates has been associated with thrombosis. Plasma markers of coagulation activation were measured before and 30, 60, 120 and 240 min after six infusions of the BPL factor XI concentrate. Five studies were completed before surgical intervention, one was undertaken in a patient with an intracerebral haemorrhage. Significant elevation of levels of fibrinopeptide A (FpA) ( P  < 0.05) and thrombin–antithrombin (TAT) were demonstrated following six infusions and prothrombin fragment F1.2 following four. Levels of all three markers had risen 60 min following concentrate administration and FpA levels remained elevated throughout the study period. Levels of D-dimer rose in four patients at 240 min. These results indicate significant thrombin generation by 60 min and subsequent plasmin generation consistent with coagulation activation by the factor XI concentrate. The greatest elevation of activation markers was seen in those subjects with pre-existing coagulation activation. We advise caution in the use of these products and awareness of the risks in patients who may already have activated coagulation states.