Plasma tissue-type plasminogen activator increases fibrinolytic activity of exogenous urokinase-type plasminogen activator

Modified Rotational Thromboelastometry Protocol Using Tissue Plasminogen Activator for Detection of Hypofibrinolysis and Hyperfibrinolysis

Viscoelastic testing includes thromboelastography (TEG^®) and thromboelastometry (ROTEM^®) and is widely used in bleeding patients to detect hypocoagulability and guide transfusion therapy. However, the ability of standard viscoelastic tests to assess fibrinolytic capacity is limited. We here describe a modified ROTEM^® protocol with addition of tissue plasminogen activator that can be used to identify hypofibrinolysis or hyperfibrinolysis.

Biomarkers of Inflammation, Thrombogenesis, and Collagen Turnover in Patients With Atrial Fibrillation

The purpose of this study was to determine whether there are any differences in the levels of inflammatory, thrombotic, and collagen turnover biomarkers between individuals with atrial fibrillation (AF) and healthy volunteers. Circulating plasma levels of plasminogen activator inhibitor 1 (PAI-1), CD40-ligand (CD40-L), nucleosomes (which are indicators of cell death), C-reactive protein (CRP), procollagen III N-terminal propeptide (PIIINP), procollagen III C-terminal propeptide (PIIICP), procollagen I N-terminal propeptide, tissue plasminogen activator, and von Willebrand factor were analyzed as potential biomarkers of AF. Baseline plasma was collected from patients with AF prior to ablation surgery at Loyola University Medical Center. Individuals with AF had statistically significantly increased levels of PAI-1, CD40-L, and nucleosomes, when compared to the normal population (P < .0001). Additionally, there was a statistically significant increase in the CRP (P = .01), PIIINP (P = .04), and PIIICP (P = .0008) when compared to normal individuals. From this study, it is concluded that the prothrombotic, inflammatory, and collagen turnover biomarkers PAI-1, CD40-L, nucleosomes, CRP, PIIICP, and PIIINP are elevated in AF.

Association between uremic toxin-anthranilic acid and fibrinolytic system activity in predialysis patients at different stages of chronic kidney disease

PURPOSE

Chronic kidney disease (CKD) is an estimated risk factor for increased mortality and morbidity due to fibrinolytic system disturbances. Progressive loss of renal function leads to retention of uremic toxins. Anthranilic acid (AA) is a tryptophan-derived uremic toxin with multidirectional properties that can affect the hemostatic system. The goal of this study was to examine the association between AA and the parameters of fibrinolysis at different stages of CKD.

METHODS

Patients with CKD were divided into two groups: mild-to-moderate (n = 20) and severe-to-end-stage CKD (n = 28). Seventeen healthy volunteers served as an additional control group. Parameters of fibrinolysis, inflammation, and monocytes activation were determined by ELISA immune-enzymatic kits. AA levels were evaluated using high-performance liquid chromatography.

RESULTS

AA concentration and parameters of fibrinolysis: urokinase-type plasminogen activator (uPA), its soluble receptor (suPAR), tissue plasminogen activator (tPA), tissue plasminogen activator inhibitor-1 (PAI-1) and plasmin-antiplasmin complex (PAP) were significantly elevated in the CKD groups compared with the controls. The markers of inflammation, monocyte activation, and impaired kidney function were also increased in those with CKD. AA was positively correlated with the uPA/suPAR system in the early stages of CKD, whereas during severe-to-end-stage CKD, inverse relationships were observed between AA, tPA and PAI-1. Additionally, AA was an independent variable associated with tPA in patients with CKD overall and with uPA levels in the mild-to-moderate CKD group.

CONCLUSIONS

Obtained results suggest for the first time the association between AA and the fibrinolytic system in CKD patients. The distinct relationship between AA and individual parameters of fibrinolysis appears to be dependent on CKD stage.

Endovenous Laser Ablation of Varicose Veins Preserves Biological Properties of Vascular Endothelium and Modulates Proinflammatory Agent Profile More Favorably Than Classic Vein Stripping

Here we compared effect of serum from varicose patients undergoing endovenous laser ablation (EVLA) and classic vein stripping (CVS) on biological properties of endothelial cells and on the local and systemic profiles of proinflammatory agents. Results showed that serum from EVLA patients improved proliferation and reduced senescence and oxidative stress in the endothelial cells, as compared with the serum from CVS patients. These effects were related to a suppressed activity of TGF-β1, the level of which in the serum from the EVLA patients was decreased. Medium generated by the cells subjected to EVLA serum contained decreased amounts of ICAM-1, VCAM-1, and E-selectin and increased amount of uPA, whereas the serum itself contained decreased concentrations of ICAM-1, E-selectin, and P-selectin and increased concentrations of uPA, PAI-1, and TFPI. Both EVLA and CVS resulted in diversified patients' reaction with respect to a direction of postprocedure changes in proinflammatory factors' serum level. Analysis of proportions showed that the groups differed remarkably in case of ICAM-1 and ET-1, the level of which declined in a higher fraction of patients treated endovenously. Our findings indicate that EVLA preserves better than CVS the functionality of vascular endothelium and modulates better both local and systemic profile of proinflammatory mediators.

Investigation of the roles of trace elements during hepatitis C virus infection using protein-protein interactions and a shortest path algorithm

BACKGROUND

Hepatitis is a type of infectious disease that induces inflammation of the liver without pinpointing a particular pathogen or pathogenesis. Type C hepatitis, as a type of hepatitis, has been reported to induce cirrhosis and hepatocellular carcinoma within a very short amount of time. It is a great threat to human health. Some studies have revealed that trace elements are associated with infection with and immune rejection against hepatitis C virus (HCV). However, the mechanism underlying this phenomenon is still unclear.

METHODS

In this study, we aimed to expand our knowledge of this phenomenon by designing a computational method to identify genes that may be related to both HCV and trace element metabolic processes. The searching procedure included three stages. First, a shortest path algorithm was applied to a large network, constructed by protein-protein interactions, to identify potential genes of interest. Second, a permutation test was executed to exclude false discoveries. Finally, some rules based on the betweenness and associations between candidate genes and HCV and trace elements were built to select core genes among the remaining genes.

RESULTS

12 lists of genes, corresponding to 12 types of trace elements, were obtained. These genes are deemed to be associated with HCV infection and trace elements metabolism.

CONCLUSIONS

The analyses indicate that some genes may be related to both HCV and trace element metabolic processes, further confirming the associations between HCV and trace elements. The method was further tested on another set of HCV genes, the results indicate that this method is quite robustness.

GENERAL SIGNIFICANCE

The newly found genes may partially reveal unknown mechanisms between HCV infection and trace element metabolism. This article is part of a Special Issue entitled "System Genetics" Guest Editor: Dr. Yudong Cai and Dr. Tao Huang.

Validation of a modified thromboelastometry approach to detect changes in fibrinolytic activity

Background

Thus far, validated whole blood assays used in in vitro fibrinolysis experiments using thromboelastometry (ROTEM) are lacking or have yet to be tested in humans.

The objective was first, to establish a standardized modified ROTEM approach to detect both hypo- and hyperfibrinolysis. And second, to perform a technical and clinical validation of the assay.

Methods

Blood was used of healthy volunteers, patients with sepsis, patients after cardiothoracic surgery, pregnant women, and cirrhotic liver disease patients. A whole blood tissue factor (TF) activated ROTEM assay with and without the addition of recombinant tissue plasminogen activator (rTPA) was developed. Plasma fibrinolysis determinants were measured in all volunteers and patients.

Results

Thirty five pM TF and additions of 125 and 175 ng/ml rTPA resulted in full lysis within 60 min in healthy volunteers. Coefficients of variation were below 10 % without and below 20 % with rTPA addition. In sepsis the hypofibrinolytic ROTEM profiles with 175 ng/ml rTPA were in line with the plasma determinants (high PAI-1, high fibrinogen, low tPA activity, and high d-dimers). After cardiothoracic surgery, reduced fibrinogen and platelet levels accounted for the reduced maximum clot firmness. The hypofibrinolytic profile is attributed to tranexamic acid use and elevated PAI-1 levels. The lowest rTPA concentration in cirrhosis resulted in hyperfibrinolysis in only few of the patients. In pregnancy normal profiles were found.

Discussion

Our high rTPA concentration demonstrates hypofibrinolytic profiles adequately in sepsis and after cardiothoracic surgery. Our low rTPA concentration of 125 ng/ml seems too high for demonstrating hyperfibrinolysis in cirrhotic liver disease.

Conclusions

We were able to present a validated whole blood ROTEM approach to fibrinolysis testing using added rTPA, which can be of added value next to classical plasma based fibrinolysis assays.

Effect of adenovirus‑mediated uPA gene transduction on the fibrinolytic activity of human umbilical vein endothelial cells

The present study aimed to investigate the effect of adenovirus‑mediated urokinase‑type plasminogen activator (uPA) transduction on uPA expression and fibrinolytic activity in human umbilical vein endothelial cells (HUVECs). Recombinant adenovirus vectors containing the human uPA gene were constructed and transduced into HUVECs. The expression and fibrinolytic activity of uPA was then assessed in HUVECs using western blot analysis, ELISA and colorimetric assay. The experiments were performed in three groups: The ad/uPa (n=3), ad/neg control (n=3) and blank control (n=3) groups. Western blot analysis revealed that uPA protein expression in the HUVECs in the ad/uPa group was significantly increased compared with those in the ad/neg control or blank groups (P<0.01). The uPA protein levels in the supernatant of the three groups were 379.40±2.46, 240.01±1.16 and 256.10±3.04 ng/l, respectively, showing that the uPA protein levels were significantly higher in the supernatant in the ad/uPa group compared with those in the ad/neg control or blank groups. uPA activity was determined using a colorimetric method and was found to be 40238.49±5755 IU/mg in the HUVECs in the ad/uPa group, which was significantly higher than that in the HUVECs in the ad/neg control (6180.03±942.38 IU/mg) or blank groups (3346.06±928.81 IU/mg) (both P<0.01). These findings suggested that transduction of the uPA gene increased uPA protein expression and fibrinolytic activity in HUVECs.