OBJECTIVETo study the mechanism of restenosis after angioplasty and to clarify the effect of thrombin and its receptor on restenosis development.

METHODSBalloon catheter-induced injury was adopted to induce intimal hyperplasia of the carotid arteries in rats. Antisense thrombin receptor (ATR) cDNA was transfected by perfusing recombinant LXSN ATR plasmid/nanoparticle complex into the segment of the injured carotid artery.

RESULTSPCR result showed integration of the recombined gene. Dot blot showed the expression of antisense TR mediated by recombinant LXSN ATR plasmid/nanoparticle complex in the wall of common carotid arteries of the experimental group rats, which enabled to inhibit TR gene expression and intimal hyperplasia of the injured arteries.

CONCLUSIONSThrombin and its receptor play an important role in the formation of neointima after the injury, which provides a potential clue in developing a new approach for prevention and treatment of restenosis after angioplasty.

Animals ; Carotid Arteries ; Hyperplasia ; Rats ; Receptors, Thrombin ; metabolism ; Thrombin ; pharmacology ; Tunica Intima ; metabolism

This study was aimed to investigate the growth-promoting activity of thrombin on mesenchymal stem cells (MSC) and its mechanisms. Human bone marrow MSC were cultured in serum-free medium supplemented with graded concentrations of thrombin, and the proliferation status of MSC was detected by MTT test. The expression levels of protease-activated receptors (PAR) and c-MYC gene were detected by PCR. Activated Akt signaling pathway was revealed by Western blot, and specific inhibitors of the signaling pathways were used to confirm the effects. The results showed that thrombin stimulated MSC proliferation in a dose-dependent manner; the minimal concentration of thrombin for stimulating MSC growth was 0.5 U/ml, and the promoting effect reached its maximum when thrombin at a dose of 8 U/ml was employed. PCR results showed that MSC expressed the two types of PAR1 and PAR2. After PAR1 was blocked with a specific inhibitor SCH79797, the growth-promoting effect of thrombin was inhibited, while this phenomenon was not observed when MSC were exposed to FSLLRY-NH2, a specific inhibitor for PAR2. Further experiments showed that after exposure to thrombin, the AKT signaling pathway in MSC was promptly activated, and c-MYC expression was greatly up-regulated. Meanwhile, when LY294002, a specific AKT inhibitor, was added into the culture medium, the up-regulation of c-MYC expression was reduced, accompanied by the low rate of MSC growth. It is concluded that thrombin can stimulate MSC proliferation by eliciting PAR1-mediated AKT activation and subsequent up-regulation of c-MYC expression.
Bone Marrow Cells ; cytology ; Cell Proliferation ; drug effects ; Cells, Cultured ; Humans ; Mesenchymal Stromal Cells ; cytology ; Receptors, Thrombin ; metabolism ; Signal Transduction ; drug effects ; Thrombin ; pharmacology

OBJECTIVETo investigate the roles of protease-activated receptors (PARs) in thrombin-induced brain injury and neurogenesis in rats.

METHODSNinety male SD rats were randomly assigned to receive intra-hippocampus injection of NS, thrombin or specific agonists of 3 protease-activated receptors (PAR-1, PAR-3 and PAR-4), respectively. At 1,3 and 7 d after injection, the area of the hippocampus was determined with HE staining, the density and morphology of astrocyte were detected with GFAP staining, degenerated neurons were detected with Fluoro-Jade C staining, and the neurogenesis was examined with DCX staining.

RESULTSCompared to NS injection, the area of the hippocampus significantly increased at 1-3 d and decreased at 7 d after the injection of thrombin and PAR-1 agonist (P<0.05). In addition, injection of thrombin and PAR-1 agonist significantly increased the density of astrocyte and Fluoro-Jade C positive cells at 1-7 d after injection (P<0.05), and significantly increased the density of DCX positive cells at 3-7 d after injection(P<0.05). The injection of PAR-3 agonist and PAR-4 agonist had no affect on the area of the hippocampus, the density of astrocyte, Fluoro-Jade C positive cells and DCX positive cells.

CONCLUSIONThe activation of protease-activated receptor-1 may be related to the thrombin-induced brain injury and neurogenesis in rat hippocampus.

Animals ; Brain Injuries ; chemically induced ; metabolism ; pathology ; Hippocampus ; pathology ; Male ; Neurogenesis ; drug effects ; Rats ; Rats, Sprague-Dawley ; Receptor, PAR-1 ; agonists ; physiology ; Receptors, Thrombin ; agonists ; Thrombin ; toxicity

AIMTo provide proof for Evidence-based Medicine as well quality control, our laboratory detected the thrombin activity on various body position.

METHODSBy autogenous contrast and cross matched survey, 105 volunteers divided into 3 season patches of winter, spring and summer, blood samples were drawn from the same part in both standing and lying position. Both samples and the quality control were detected to investigate the effect of the body position to thrombin activity's changing. The data were analyzed by SPSS 10.0.

RESULTSTaking the lying's data as baseline, the average changing on all those the "5" index was 7.07% and the highest changing reached 9.33%. This kind changing had great significant differences (P < 0.01). According to the t value, sequences ranged: FIB > TT > PT > INR > APTT. FIB, TT and APTT's values slowly raised, adversely PT and INR slowly went down. While sitting for 15 min after lying, these indices returned to 95.2% of the original value in sitting position in addition. Season, age and device had no relationship with body position.

CONCLUSIONChanging body position can result in obvious physiological variation of thrombin activity.

Adult ; Evidence-Based Medicine ; Female ; Humans ; Male ; Middle Aged ; Posture ; physiology ; Thrombin ; metabolism

OBJECTIVESTo investigate molecular mechanisms of PAR-1 regulation on intracellular Ca²(+) mobilization in lung giant cell carcinoma cells in vitro and its involvement in tumor metastasis.

METHODSFree intracellular Ca²(+) ([Ca²(+)]i) was measured in lung giant cell carcinoma PLA801C and PLA801D cells by confocal microscopy. Sense and anti-sense PAR-1 expression vectors were transfected into PLA801C (C+)and PLA801D(D-) cells, respectively. The effects of PAR-1 expression were investigated by thrombin and TRAP-induced mobilization of [Ca²(+)]i in the C+ and D-cells.

RESULTSThere were significant differences of the mean values of [Ca²(+)]i between PLA801D (59.55) and PLA801C cells (35.46, P < 0.01). The mean [Ca²(+)]i of C+ cells (45.77) was significantly higher than that of its control CV cells (35.46, P < 0.05), and the mean [Ca²(+)]i of D-cells (48.42) was significantly lower than that of its control DV cells (59.55, P < 0.05). The peaks of [Ca²(+)]i of C+ and CV cells were 48.19 ± 9.84 and 45.64 ± 9.87 (P < 0.05) respectively at 80 s and 100 s after thrombin treatment, but were 111.31 ± 25.00 and 52.93 ± 11.21 (P < 0.05) respectively at 60 s after TRAP treatment. The peaks of [Ca²(+)]i of D- and DV cells were 40.71 ± 5.89 and 61.07 ± 21.36 (P < 0.05) respectively at 60 s after thrombin treatment, but were 84.98 ± 11.23 and 102.58 ± 21.48 (P < 0.05) respectively at 40 s after TRAP treatment.

CONCLUSIONSThe high metastatic potential of PLA801D and PLA801C may be related to [Ca²(+)]i of the tumor cells. PAR-1 may play an important role in the metastasis of lung giant cell carcinoma cells by up-regulating the intracellular Ca²(+).

Calcium ; metabolism ; Calcium Signaling ; drug effects ; Carcinoma, Giant Cell ; metabolism ; pathology ; Cell Line, Tumor ; DNA, Antisense ; genetics ; Humans ; Lung Neoplasms ; metabolism ; pathology ; RNA, Messenger ; metabolism ; Receptor, PAR-1 ; genetics ; metabolism ; physiology ; Receptors, Thrombin ; metabolism ; Thrombin ; pharmacology ; Transfection ; Up-Regulation

AIMTo study the dynamic and long-lasting expression of thrombin receptor after acute intracerebral hemorrhage (ICH) in rats.

METHODS36 rats were randomly divided into 6 groups (n = 6): Normal group and ICH model groups at 6 hours, 24 hours, 3 days, 7 days and 14 days. ICH models were produced with the induction of collagenase type VII-S. Immunohistochemical method was used to detect PAR-1 protein and RT-PCR technique was used to detect PAR-1mRNA in brain tissue around the haematoma in different groups.

RESULTSPAR-1 protein and mRNA were mild positive in normal group. In model groups, intensity of PAR-1 expression started to enhance at 6 hours, and enhanced more at 24 hours. PAR-1 expression reached the peak at 3 days and began to descend. At 7 days the descent was obvious and there was further descent at 14 days. At each time point, the PAR-1 protein positive cell number and PAR-1mRNA absorbance ratio in ICH model groups were significantly higher than those in normal group (P < 0.05 or P < 0.01). In addition, PAR-1 proteins were obviously expressed in vivo in brain capillary endothelial cell.

CONCLUSIONFunctional PAR-1 exists in brain capillary endothelial cells. Activation of PAR-1 after ICH due to the stimulation of thrombin is not only the initiating agent of cerebral edema after ICH, but also participates the development of cerebral edema.

Animals ; Cerebral Hemorrhage ; metabolism ; Disease Models, Animal ; Male ; Rats ; Rats, Wistar ; Receptor, PAR-1 ; metabolism ; Thrombin ; metabolism

The aberrant protein crosslinks formation during lung injury as results total body irradiation (TBI) and bone marrow transplantation (BMT) therapy has been examined as apossible contributory factor in organ or tissue pathogenesis. Female C3HeB/ FeJ mice were used for an experimental animal. Carbon monoxide uptake (V(CO)) was measured at 1, 2, 3, 4 and 5 months after TBI at respective doses of 12, 14, 16 and 18 Gy 16 h prior to syngeneic BMT. Also as a measure of aberrant protein crosslinking in the inured tissues, transglutaminase (TGase)-activities and crosslinked protein were examined along with thrombin, a protease known to activate TGases. Reductions of VCO were detected following TBI and BMT. Activities of thrombin and TGase 1, and crosslinked protein in bronchoalveolar lavage (BAL) fluid of the mice 1 wk after TBI at 12 Gy and BMT were identified and found to be elevated in the treated animals. These findings suggest that elevated levels of crosslinked proteins and TGase I in the bronchoalveolar larvage during the lung injury could have enhanced the organ pathogenesis following TBI and BMT.
Animals ; *Bone Marrow Transplantation ; Carbon Monoxide/metabolism ; Factor XIII/metabolism ; Female ; Lung/*metabolism/pathology/radiation effects ; *Lung Injury ; Mice ; Proteins/*metabolism ; Thrombin/metabolism ; Transglutaminases/metabolism ; *Whole-Body Irradiation

OBJECTIVETo study the relationship between the expressions of thrombin-antithrombin (TAT) complex and excess syndrome of stroke (ESS) and depletion syndrome of stroke (DSS) by dynamically observing the expressions of TAT complex in the plasma and hematoma fluid of intracerebral hemorrhage (ICH) patients.

METHODSSixty patients were assigned to three groups according to syndrome typing, i.e., as yang excess group (18 cases), yin excess group (22 cases), and depletion syndrome group (20 cases). The hemorrhage volume was assessed. NIHSS and GCS were scored. Besides, 30 healthy volunteers at the Physical Examination Center, Second People's Hospital Affiliated to Fujian University of Traditional Chinese Medicine were recruited as the normal control group. Another 10 patients in need of lumbal anesthesia were recruited as the cerebrospinal fluid control group, who suffered from surgical, gynecologic pelvic diseases, or diseases from lower limbs, but unaccompanied with cardio-/cerebrovascular diseases. The expressions of TAT complex were detected in the venous blood and hematoma fluid of the patient groups and in the venous blood or the cerebrospinal fluid of the control group using ELISA.

RESULTSThe syndromes were sequenced as the depletion syndrome > the yin excess syndrome > the yang excess syndrome according to the hemorrhage volume and NIHSS score. They were sequenced as the yang excess syndrome > the yin excess syndrome >the depletion syndrome according to the GCS score. The plasma TAT complex content on the 4th day in the ICH group was lower than that at the rest time points, showing statistical significance (P<0.01). Compared with the normal control group, the plasma TAT complex on the 1st, 2nd, and 4th day all increased with statistical difference (P<0.01). Statistical significance of the TAT complex in the hematoma fluid of the ICH group existed when compared it on the 1st, 2nd, and 4th day (P<0.01). Compared with the cerebrospinal fluid control group, the contents of the TAT complex in the hematoma fluid of the ICH group increased with statistical difference (P<0.01). The hemorrhage volume of ICH patients was positively correlated with NIHSS (r=0.809, P<0.01) and negatively correlated with GCS (r=-0.833, P<0.01). The TAT complex was obviously higher in the ICH group than in the two control groups in a dynamic way (P<0.01). There was obvious difference in the expressions of TAT among yang excess group, yin excess group, and depletion syndrome group (P<0.01). The expressions of TAT in the plasma and the hematoma fluid of the ICH group were negatively correlated with GCS score and positively correlated with NIHSS score (both P<0.01).

CONCLUSIONSTAT complex participated in secondary neuron injury after ICH, which could be taken as an objective index for clinical observation. It also could provide evidence for syndrome quantification of excess syndrome and depletion syndrome.

Antithrombin III ; metabolism ; Case-Control Studies ; Cerebral Hemorrhage ; blood ; diagnosis ; metabolism ; Hematoma ; blood ; diagnosis ; metabolism ; Humans ; Medicine, Chinese Traditional ; Peptide Hydrolases ; metabolism ; Stroke ; blood ; diagnosis ; metabolism ; Thrombin ; metabolism

OBJECTIVES: The coagulation and fibrinolytic system appears to be activated by the septic process independently, leading to the syndrome of disseminated intravascular coagulation (DIC). In this study, we investigated the changes within the hemostatic system related to the severity of the illness and the prognosis in patients with sepsis. METHODS: Plasma thrombin-antithrombin III (TAT) and plasmin-alpha 2-antiplasmin (PAP) complexes were measured using ELISA methods in 32 patients with sepsis and 20 controls and were analyzed according to the APACHE III scores and survival of the patients. RESULTS: Plasma TAT and PAP in patients with sepsis were significantly higher than controls. Nonsurvivors showed greater levels of TAT (21.7 +/- 22.3 ng/mL) and lower levels of PAP (628.4 +/- 378.1 ng/mL) than survivors (TAT: 11.1 +/- 11.2 ng/mL; PAP: 857.1 +/- 364.1 ng/mL). The imbalance between coagulation and fibrinolysis described as TAT/PAP ratio was closely related with APACHE III scores in patients with sepsis (r = 0.47) and the TAT/PAP ratio in nonsurvivors was significantly higher compared with survivors (34.4 +/- 21.4 vs. 14.4 +/- 13.8). CONCLUSION: In sepsis, both coagulation and the fibrinolysis system are activated and the imbalance between coagulation and fibrinolysis predisposes to the hypercoagulation state and is closely related to the severity of the disease and the prognosis.
Adult ; Aged ; Antiplasmin/metabolism ; Antithrombin III/metabolism ; Blood Coagulation* ; Case-Control Studies ; Female ; Fibrinolysis* ; Human ; Male ; Middle Age ; Plasmin/metabolism ; Prognosis ; Sepsis/blood* ; Thrombin/metabolism

Thrombin-like enzymes (TLEs) are studied widely because of their therapeutic potential in myocardial infarction and thrombotic diseases. We synthesized the DNA fragment encoding thrombin-like enzyme calobin from Agkistrodon caliginosus (Korean Viper) venom by fusion PCR and expressed it in Pichia pastoris. After induction by 0.5% methanol for 48 h, the expression level of recombinant calobin reached 3.5 g/L in medium. The recombinant calobin was purified by Q-Sepharose Fast Flow ion-exchange chromatography and Sephacryl-S-100 gel filtration chromatography. Purified sample had a molecular weight of 32 kD shown in SDS-PAGE. It hydrolyzed fibrinogen and formed a light white hydrolysis circle in fibrinogen plate. SDS-PAGE analysis showed that recombinant calobin cleaved Aalpha-chain of fibrinogen specifically, and produced an appropriately 40 kD new band. However, we failed to find its fibrin-clot formation activity.
Agkistrodon ; Animals ; Pichia ; genetics ; metabolism ; Recombinant Proteins ; biosynthesis ; genetics ; Serine Endopeptidases ; biosynthesis ; genetics ; Thrombin ; biosynthesis ; genetics ; Viper Venoms ; enzymology