Wenning Wei

Plasma Thrombomodulin, Fibrinogen, and Activity of Tissue Factor as Risk Factors for Acute Cerebral Infarction

Several studies have indicated association between hematologic markers and increased risks of cerebrovascular disease, but few reports referred to their roles together. We studied plasma levels of 16 hematologic markers in 50 cases diagnosed as acute cerebral infarction (ACI) and 54 hospital control subjects. Plasma levels of thrombomodulin, fibrinogen, and activity of tissue factor (aTF) were significantly higher in cases than in control subjects (P < .001, P < .01, and P < .05, respectively). Multivariate logistic regression analysis showed that hypertension and high plasma levels of thrombomodulin, fibrinogen, and aTF were significantly associated with presence of ACI (odds ratio [OR], 143.74, P < .001; OR, 2.05, P < .05; OR, 2.09, P < .05; OR, 1.02, P < .05, respectively). Our findings indicate that hypertension and elevation of plasma thrombomodulin, fibrinogen, and aTF are independent risk factors for ACI.

Thrombin Activatable Fibrinolysis Inhibitor in Preeclmapsia and Gestational Hypertension throughout the Gestation

SummaryTo clarify the role of TAFI in hypertensive disorders in pregnancy, 22 subjects, including 10 with pre-eclampsia (PE) and 12 with gestational hypertension were examined for the levels of TAFI and thrombin-antithrombin (TAT) complex. Thirty normal pregnant women served as controls. ELISA was employed for the detection. The results showed that the TAFI antigen levels in normal pregnancy group, gestational hypertension group and PE group were (85.35±24.69)%, (99.65±18.27)%, (110.12±23.36)%; (97.06±21.40)%, (114.08±27.76)%, (125.49±24.70)%; (106.6±19.21)%, (129.2±25.07)%, (139.1±30.12)%, in the 1st, 2nd and 3rd trimester respectively. No significant differences were found between the normal pregnancy group and gestational hypertension group but significant difference existed between normal pregnancy group and PE group in each trimester (P<0.05). TAT complexes were significantly higher in patients with PE than that in controls (P<0.05), but no correlation was found between TAT and TAFI. It is concluded that TAFI may contributed to the impairment of fibrinolysis in the patients with PE and may serves as a sensitive indicator for PE, but it may not help in the diagnosis of the gestational hypertension.To clarify the role of TAFI in hypertensive disorders in pregnancy, 22 subjects, including 10 with pre-eclampsia (PE) and 12 with gestational hypertension were examined for the levels of TAFI and thrombin-antithrombin (TAT) complex. Thirty normal pregnant women served as controls. ELISA was employed for the detection. The results showed that the TAFI antigen levels in normal pregnancy group, gestational hypertension group and PE group were (85.35±24.69)%, (99.65±18.27)%, (110.12±23.36)%; (97.06±21.40)%, (114.08±27.76)%, (125.49±24.70)%; (106.6±19.21)%, (129.2±25.07)%, (139.1±30.12)%, in the 1st, 2nd and 3rd trimester respectively. No significant differences were found between the normal pregnancy group and gestational hypertension group but significant difference existed between normal pregnancy group and PE group in each trimester (P<0.05). TAT complexes were significantly higher in patients with PE than that in controls (P<0.05), but no correlation was found between TAT and TAFI. It is concluded that TAFI may contributed to the impairment of fibrinolysis in the patients with PE and may serves as a sensitive indicator for PE, but it may not help in the diagnosis of the gestational hypertension.

Use of PEI-coated Magnetic Iron Oxide Nanoparticles as Gene Vectors

SummaryTo evaluate the feasibility of using polyethyleneimine (PEI) coated magnetic iron oxide nanoparticles (polyMAG-1000) as gene vectors. The surface characteristics of the nanoparticles were observed with scanning electron microscopy. The ability of the nanoparticles to combine with and protect DNA was investigated at different PH values after polyMAG-1000 and DNA were combined in different ratios. The nanoparticles were tested as gene vectors with in vitro transfection models. Under the scanning electron microscope the nanoparticles were about 100 nm in diameter. The nanoparticles could bind and condense DNA under acid, neutral and alkaline conditions, and they could transfer genes into cells and express green fluorescent proteins (GFP). The transfection efficiency was highest (51%) when the ratio of nanoparticles to DNA was 1∶1 (v∶w). In that ratio, the difference in transfection efficiency was marked depending on whether a magnetic field was present or not: about 10% when it was absent but 51% when it was present. The magnetic iron oxide nanoparticles coated with PEI may potentially be used as gene vectors.

An oligonucleotide decoy for nuclear factor-κB inhibits tumor necrosis factor-α-induced human umbilical cord vein endothelial cell tissue factor expression in vitro

Abnormal tissue factor (TF) expression on vascular endothelial cells may account for thrombotic events associated with cardiovascular disease. The transcription factor nuclear factor-kappa B (NF-kappa B) activation plays a key role in endothelial cell injury and TF expression. Disruption of NF-kappa B activation in endothelial cells may inhibit TF expression and be protective in thrombosis. The purpose of the study was to determine whether NF-kappa B transcription factor decoy (TFD) could block TF expression. NF-kappa B TFD was transferred into cultured human umbilical cord vein endothelial cells (HUVEC) by liposomes, and the transfection efficiency was detected by flow cytometry. The effect of NF-kappa B TFD on TF mRNA levels was determined by reverse transcription-polymerase chain reaction. The expression of surface TF antigen was analyzed by flow cytometry. TF activity was studied by measuring enzymatic activation of factor X by the TF-activated factor VII complex. The results suggested that NF-kappa B decoy could be successfully transferred into HUVEC by liposome. The NF-kappa B TFD competed with the endogenous kappa B site sequence in the TF promoter for binding to transcription factor NF-kappa B in tumor necrosis factor-alpha-stimulated HUVEC, which could block the tumor necrosis factor-alpha-induced increase in TF mRNA levels, the upregulation of surface TF antigen and TF activity. This study demonstrated that NF-kappa B decoy could block HUVEC TF gene expression. Targeted genetic disruption of endothelial TF expression by NF-kappa B decoy may provide a possible therapeutic method for cardiovascular and thrombosis disease.

Relationship between acquired deficiency of vitamin K-dependent clotting factors and hemorrhage

This study examined the changes of activities of vitamin K-dependent clotting factors (VKDCF) under various pathological conditions and explored the relationship between acquired deficiency of VKDCFs and hemorrhage. Clinical data of 35 patients who were diagnosed as having acquired deficiency of VKDCF were retrospectively analyzed. Coagulation factors involved in the intrinsic and extrinsic pathways were detected in these patients and 41 control subjects. The results showed that the average activities of VKDCFs were decreased in the patients in comparison to the control subjects and significantly increased after treatment of these patients with vitamin K and blood products. Multivariate regression analysis indicated that decreased activity of VKDCF was not an independent risk factor for bleeding disorders owing to deficiency or metabolic disturbance of vitamin K. It was concluded that acquired deficiency of VKDCF occurs under a variety of pathologic conditions and is closely associated with hemorrhagic events. Administration of vitamin K and transfusion of blood products containing high concentrations of VKDCFs helps alleviate the hemorrhagic diseases.SummaryThis study examined the changes of activities of vitamin K-dependent clotting factors (VKDCF) under various pathological conditions and explored the relationship between acquired deficiency of VKDCFs and hemorrhage. Clinical data of 35 patients who were diagnosed as having acquired deficiency of VKDCF were retrospectively analyzed. Coagulation factors involved in the intrinsic and extrinsic pathways were detected in these patients and 41 control subjects. The results showed that the average activities of VKDCFs were decreased in the patients in comparison to the control subjects and significantly increased after treatment of these patients with vitamin K and blood products. Multivariate regression analysis indicated that decreased activity of VKDCF was not an independent risk factor for bleeding disorders owing to deficiency or metabolic disturbance of vitamin K. It was concluded that acquired deficiency of VKDCF occurs under a variety of pathologic conditions and is closely associated with hemorrhagic events. Administration of vitamin K and transfusion of blood products containing high concentrations of VKDCFs helps alleviate the hemorrhagic diseases.

Down-regulation of tissue factor by siRNA increased doxorubicin-induced apoptosis in human neuroblastoma

SummaryThe effects of tissue factor (TF) on doxorubicin-induced apoptosis in human neuroblastoma were investigated. The expression of TF was examined by Western blotting. TFsiRNA-pSUPER plasmid was constructed by inserting specific 19-nt silencing sequence targeting TF gene into pSUPER vector. Transfection of TFsiRNA-pSUPER was performed using lipofectamine2000. The cytotoxicity of doxorubicin was determined by WST assay. The activation of Caspase-3 and PARP induced by doxorubicin was tested by Western blotting. The apoptotic cells were stained by Hochest33342 and counted under fluorescence inverted microscope. It was found that human neuroblastoma cell line SK-N-MC expressed high level of TF. Knockdown of the TF expression was achieved by transfection of TFsiRNA-pSUPER on SK-N-MC cells in a dose-dependent manner. Inhibition of TF significantly decreased the viability of transfected SK-N-MC cells treated with different concentrations of doxorubicin. Cleavage of Caspase-3 and PARP was enhanced in transfected SK-N-MC cells with down-regulation of TF. TFsiRNA treatment significantly increased the number of apoptotic cells in transfected SK-N-MC cells as compared with those control cells (P<0.05) when these cells were exposed to 1 μg/mL doxorubicin for 8 h. These results suggested that knockdown of the TF expression by specific siRNA vector could increase the cytotoxicity of doxorubicin and enhance doxorubicin-induced apoptosis in human neuroblastoma cells. Over-expression of TF might contribute to chemotherapy resistance in human neuroblastoma and its progression, at lest in part, by regulating doxorubicin-induced apoptosis.The effects of tissue factor (TF) on doxorubicin-induced apoptosis in human neuroblastoma were investigated. The expression of TF was examined by Western blotting. TFsiRNA-pSUPER plasmid was constructed by inserting specific 19-nt silencing sequence targeting TF gene into pSUPER vector. Transfection of TFsiRNA-pSUPER was performed using lipofectamine2000. The cytotoxicity of doxorubicin was determined by WST assay. The activation of Caspase-3 and PARP induced by doxorubicin was tested by Western blotting. The apoptotic cells were stained by Hochest33342 and counted under fluorescence inverted microscope. It was found that human neuroblastoma cell line SK-N-MC expressed high level of TF. Knockdown of the TF expression was achieved by transfection of TFsiRNA-pSUPER on SK-N-MC cells in a dose-dependent manner. Inhibition of TF significantly decreased the viability of transfected SK-N-MC cells treated with different concentrations of doxorubicin. Cleavage of Caspase-3 and PARP was enhanced in transfected SK-N-MC cells with down-regulation of TF. TFsiRNA treatment significantly increased the number of apoptotic cells in transfected SK-N-MC cells as compared with those control cells (P<0.05) when these cells were exposed to 1 μg/mL doxorubicin for 8 h. These results suggested that knockdown of the TF expression by specific siRNA vector could increase the cytotoxicity of doxorubicin and enhance doxorubicin-induced apoptosis in human neuroblastoma cells. Over-expression of TF might contribute to chemotherapy resistance in human neuroblastoma and its progression, at lest in part, by regulating doxorubicin-induced apoptosis.

Homocysteine-induced enhanced expression of tissue factor in human vascular smooth muscle cells

The homocysteine (Hcy)-induced tissue factor (TF) expression in human vascular smooth muscle cells (VSMCs) and the effect of Hcy on the activity of nuclear factor-kappaB (NF-κB) and the expression of inducible nitric oxide synthase (iNOS) were investigated. Human umbilical artery VSMCs were cultured by tissue explanting method, identified by α-actin immunohistochemistry, and incubated with different concentrations of Hcy/PTDC (NF-κB inhibitor). Semi-quantitative RT-PCR was performed to detect the expression of TF mRNA in VSMCs. Flow cytometry was used to assay the expression of TF protein on the surface of VSMCs and the expression of iNOS in VSMCs. Western blot was carried out to detect the expression of NF-κB protein in nuclei. The results showed that Hcy could induce VSMCs expressing TF mRNA significantly after the VSMCs were incubated with Hcy at concentrations of 10, 100, 500 μmol/L respectively. There was low expression level of TF protein on the surface of the resting VSMCs and Hcy could also induce VSMCs expressing TF protein on the cell surface in different concentrations. Additionally, Hcy could rapidly induce the activation of NF-κB and this effect could be significantly inhibited by PDTC. Hcy alone could not induce the expression of iNOS in VSMCs. It was concluded that Hcy could significantly induce the expression of TF in VSMCs and enhance the activation of NF-KB, subsequently mediate TF gene expression and protein synthesis. NF-κB-mediated expression of TF in VSMCs might be the important mechanism of atherosclerosis and thrombosis induced by Hcy.SummaryThe homocysteine (Hcy)-induced tissue factor (TF) expression in human vascular smooth muscle cells (VSMCs) and the effect of Hcy on the activity of nuclear factor-kappaB (NF-κB) and the expression of inducible nitric oxide synthase (iNOS) were investigated. Human umbilical artery VSMCs were cultured by tissue explanting method, identified by α-actin immunohistochemistry, and incubated with different concentrations of Hcy/PTDC (NF-κB inhibitor). Semi-quantitative RT-PCR was performed to detect the expression of TF mRNA in VSMCs. Flow cytometry was used to assay the expression of TF protein on the surface of VSMCs and the expression of iNOS in VSMCs. Western blot was carried out to detect the expression of NF-κB protein in nuclei. The results showed that Hcy could induce VSMCs expressing TF mRNA significantly after the VSMCs were incubated with Hcy at concentrations of 10, 100, 500 μmol/L respectively. There was low expression level of TF protein on the surface of the resting VSMCs and Hcy could also induce VSMCs expressing TF protein on the cell surface in different concentrations. Additionally, Hcy could rapidly induce the activation of NF-κB and this effect could be significantly inhibited by PDTC. Hcy alone could not induce the expression of iNOS in VSMCs. It was concluded that Hcy could significantly induce the expression of TF in VSMCs and enhance the activation of NF-KB, subsequently mediate TF gene expression and protein synthesis. NF-κB-mediated expression of TF in VSMCs might be the important mechanism of atherosclerosis and thrombosis induced by Hcy.

Fribrinolysis kinetics and its application.

A new, convenient, and rapid method for kinetic measurement of human fibrinolysis was established. The alteration of absorbance (A) in the process of blood coagulation and lyses was automatically scanned and recorded using a UV2000 spectrophotometer connected to a computer. The parameters of human fibrinolysis kinetics were established. Urokinase at 20 U/mL was the optimal concentration used. There was significant difference in fibrinolysis kinetics and plasma plasminogen concentration between 22 normal subjects and 27 patients with acute myeloblastic leukemia (P<0.05 and <0.01 respectively). The coefficience of variation was (5.24±1.51)%. This method could also be used to measure the plasma fibrinogen concentration at the same time. It was concluded that this method was stable and was capable of providing dynamic, direct experimental data and multiparemeters for clinicians. It was also valuable in evaluating the anti-and pro-fibrinolytic capcity of patients’ plasmas, allowing for monitoring of therapy, choice of drugs and adjustment of drug concentrations.