In resting platelets, the 17 ^th domain of filamin a (FLNa17) constitutively binds to the platelet membrane glycoprotein Ibα (GPIbα) at its cytoplasmic tail (GPIbα-CT) and inhibits the downstream signal activation, while the binding of ligand and blood shear force can activate platelets. To imitate the pull force transmitted from the extracellular ligand of GPIbα and the lateral tension from platelet cytoskeleton deformation, two pulling modes were applied on the GPIbα-CT/FLNa17 complex, and the molecular dynamics simulation method was used to explore the mechanical regulation on the affinity and mechanical stability of the complex. In this study, at first, nine pairs of key hydrogen bonds on the interface between GPIbα-CT and FLNa17 were identified, which was the basis for maintaining the complex structural stability. Secondly, it was found that these hydrogen bonding networks would be broken down and lead to the dissociation of FLNa17 from GPIbα-CT only under the axial pull force; but, under the lateral tension, the secondary structures at both terminals of FLNa17 would unfold to protect the interface of the GPIbα-CT/FLNa17 complex from mechanical damage. In the range of 0~40 pN, the increase of pull force promoted outward-rotation of the nitrogen atom of the 563 ^rd phenylalanine (PHE ⁵⁶³-N) at GPIbα-CT and the dissociation of the complex. This study for the first time revealed that the extracellular ligand-transmitted axial force could more effectively relieve the inhibition of FLNa17 on the downstream signal of GPIbα than pure mechanical tension at the atomic level, and would be useful for further understanding the platelet intracellular force-regulated signal pathway.
Filamins/metabolism* ; Platelet Glycoprotein GPIb-IX Complex/metabolism* ; Molecular Dynamics Simulation ; Ligands ; Protein Binding ; Blood Platelets/metabolism* ; von Willebrand Factor/metabolism*

OBJECTIVES: To explore the role and potential mechanisms of chitinase-3-like protein 1 (CHI3L1) in coronary artery lesions in a mouse model of Kawasaki disease (KD)-like vasculitis. METHODS: Four-week-old male SPF-grade C57BL/6 mice were randomly divided into a control group and a model group, with 10 mice in each group. The model group mice were intraperitoneally injected with 0.5 mL of lactobacillus casei cell wall extract (LCWE) to establish a mouse model of KD-like vasculitis, while the control group mice were injected with an equal volume of normal saline. The general conditions of the mice were observed on the 3rd, 7th, and 14th day after injection. Changes in coronary artery tissue pathology were observed using hematoxylin-eosin staining. The level of CHI3L1 in mouse serum was measured by enzyme-linked immunosorbent assay. Immunofluorescence staining was used to detect the expression and localization of CHI3L1, von Willebrand factor (vWF), and α-smooth muscle actin (α-SMA) in coronary artery tissue. Western blot analysis was used to detect the expression of CHI3L1, vWF, vascular endothelial cadherin (VE cadherin), Caspase-3, B cell lymphoma-2 (Bcl-2), Bcl-2 associated X protein (Bax), nuclear factor κB (NF-κB), and phosphorylated NF-κB (p-NF-κB) in coronary artery tissue. RESULTS: The serum level of CHI3L1 in the model group was significantly higher than that in the control group (P<0.05). Compared to the control group, the expression of CHI3L1 in the coronary artery tissue was higher, while the expression of vWF was lower in the model group. The relative expression levels of CHI3L1, Bax, Caspase-3, NF-κB, and p-NF-κB were significantly higher in the model group than in the control group (P<0.05). The relative expression levels of vWF, VE cadherin, and Bcl-2 were lower in the model group than in the control group (P<0.05). CONCLUSIONS In the LCWE-induced mouse model of KD-like vasculitis, the expression levels of CHI3L1 in serum and coronary arteries increase, and it may play a role in coronary artery lesions through endothelial cell apoptosis mediated by inflammatory reactions.
Male ; Animals ; Mice ; Mucocutaneous Lymph Node Syndrome/pathology* ; Coronary Vessels/pathology* ; NF-kappa B ; Caspase 3/metabolism* ; bcl-2-Associated X Protein/metabolism* ; Chitinase-3-Like Protein 1 ; von Willebrand Factor/metabolism* ; Mice, Inbred C57BL ; Cadherins

OBJECTIVE: To develop monoclonal antibodies that can specifically recognize human von Willebrand factor (VWF) propeptide (VWFpp) in plasma, and establish a rapid and reliable method for the detection of VWFpp antigen in plasma by using the double-antibody sandwich ELISA with the obtained anti-VWFpp monoclonal antibody. METHODS: The recombinant human VWFpp (D1 and D2 regions) protein expressed in eukaryotic cells was used as immunogen to immunize BALB/c mice with routine method, so as to obtain clones of fusion cells. After screening and identification, hybridoma cell lines secreting monoclonal antibodies against VWFpp were selected, and then double-antibody sandwich ELISA assay was used to construct VWFpp antigen detection kit for the determination of VWFpp in human plasma. The levels of VWFpp antigen in plasma of 12 leukemia patients who underwent bone marrow transplantation were dynamically detected. RESULTS: Two hybridoma cell lines that can be subcultured continuously and secrete monoclonal antibodies against VWFpp were obtained and named SZ175 and SZ176 respectively. Identified by ELISA and Western blot, the antibodies could both specifically recognize VWFpp but couldn't recognize mature VWF (without propeptide). Based on the principle of double-antibody sandwich ELISA, monoclonal antibodies SZ175 and SZ176 were successfully made into a kit for detecting VWFpp antigen. The plasma VWFpp levels of leukemia patients before and after bone marrow transplantation were dynamically detected. The results showed that the plasma VWFpp levels of the patients after transplantation were significantly higher than those before transplantation. CONCLUSION Two monoclonal antibodies against VWFpp were successfully prepared, and a double-antibody sandwich ELISA detection kit for VWFpp antigen was constructed, which provides a powerful tool for further study on the biological function of VWFpp, the clinical diagnosis and classification of von Willebrand disease (VWD), and the prognostic monitoring of endothelial injury-related diseases.
Animals ; Mice ; Humans ; von Willebrand Factor ; Antibodies, Monoclonal ; Protein Precursors/metabolism* ; von Willebrand Diseases/diagnosis* ; Prognosis

This study aims to observe the therapeutic effect of salidroside on cerebral ischemia-reperfusion(I/R) model rats, and to specifically explore the protection of salidroside on endothelial cell barrier after I/R and the mechanism. In the experiment, SD rats were randomized into sham group, model group, and high-, medium-, and low-dose(10, 5, and 2.5 mg·kg~(-1)) salidroside groups. The suture method was used to induce I/R in rats. The infarct area, neurobehavioral evaluation, and brain water content were used to evaluate the efficacy of salidroside. As for the experiment on the mechanism, high-dose and low-dose salidroside groups were designed. The pathological morphology was observed based on hematoxylin and eosin(HE) staining, and ultrastructure of vascular endothelial cells based on transmission electron microscopy. The content of nitric oxide(NO) in serum, four indexes of blood coagulation, and the content of von Willebrand factor(vWF) in plasma were measured. Western blot(WB) and immunofluorescence(IF) were employed to determine the expression of tight junction proteins(ZO-1, occluding, and claudin-1) and matrix metalloproteinase 9(MMP-9) in the cortex. The results showed that the model group had obvious neurological deficit, obvious infarct in the right brain tissue, and significant increase in water content in brain tissue compared with the sham group. Compared with the model group, high-dose and low-dose salidroside groups showed decrease in neurobehavioral score, and the high-, medium-, and low-dose salidroside groups demonstrated obviously small infarct area and significant decrease in water content in brain tissue. The results of HE staining and transmission electron microscopy showed that rats had necrosis of neurons, damage of original physiological structure of endothelial cells, and disintegration of the tight junction between endothelial cells after I/R compared with the sham group. Compared with the model group, the high-dose and low-dose salidroside groups showed alleviation of neuron injury and intact physiological structure of endothelial cells. The model group had significantly lower serum level of NO, significantly higher plasma levels of vWF and fibrinogen(FIB), and significantly shorter thrombin time(TT) and prothrombin time(PT) than the sham group. Compared with model group, the high-dose and low-dose salidroside groups increased the serum content of NO in serum, decreased the plasma levels of FIB and vWF, and significantly prolonged TT and PT. WB and IF results showed that the model group had significantly lower levels of ZO-1, occluding, and claudin-1 among endothelial cells and significantly higher level of MMP-9 than the sham group. Compared with the model group, high-dose and low-dose salidroside significantly increased the levels of ZO-1, occluding, and claudin-1 in the cortex. The above experimental results show that salidroside has clear therapeutic effect on I/R rats and protects the brain. To be specific, it alleviates the damage of endothelial cells by increasing NO synthesis in endothelial cells, inhibiting coagulation reaction and MMP-9 expression, up-regulating the expression of ZO-1, occludin, and claudin-1, thereby protecting the brain.
Animals ; Rats ; Matrix Metalloproteinase 9/metabolism* ; Endothelial Cells/metabolism* ; Reperfusion Injury/metabolism* ; Blood-Brain Barrier ; Claudin-1/therapeutic use* ; von Willebrand Factor/therapeutic use* ; Rats, Sprague-Dawley ; Brain Ischemia/metabolism* ; Cerebral Infarction ; Reperfusion ; Water/metabolism*

OBJECTIVE: To investigate whether co-transfection of wild-type VWFpp with VWF mutant in D1 region is able to correct VWF defects in biosynthesis and secretion. METHODS: Four VWF mutant plasmids were single transfected into HEK 293 cells, or co-transfected into HEK 293 cells with the wild type VWFpp plasmids. The VWF in supernatant and lysate of transfected cells were analyzed by ELISA, vertical VWF multimer electrophoresis. The retention of VWF in endoplasmic reticulum of transfected cells were detected by immunofluorescence confocal microscope. RESULTS: In the vertical VWF multimer analysis, with co-expressing VWF mutant and VWFpp, the VWF multimer bands disappeared, and the VWF antigen in both supernatant and lysate of cells decreased, compared with the single expression of VWF mutant. Although the intracellular levels of VWF antigens decreased after co-expression, the retention rate of VWF mutant decreased in endoplasmic reticulum. CONCLUSION VWFpp can reduce the retention of VWF in endoplasmic reticulum, assists the transport of VWF between subcellular organelles. However, VWFpp inhibits the biosynthesis and secretion of VWF about the mutant in D1 domain.
HEK293 Cells ; Humans ; von Willebrand Diseases ; von Willebrand Factor/metabolism*

OBJECTIVE: To observe the effects of histones on lung injury and von Willebrand factor (vWF) and fibrinogen (FIB) levels in mice, and to explore the protective effect of heparin. METHODS: Twenty-four male C57BL/6 mice aged 6-10 weeks were divided into control group, histone group and histone+heparin group according to random number table method with 8 mice in each group. The mice in the histone group were injected with histone (50 mg/kg) via the tail vein, and the mice in the histone+heparin group were injected with unfractionated heparin (400 U/kg) via the tail vein at 1 hour after administration of histone, and those in the control group were given the same amount of normal saline. Four hours after histone injection, the lungs of the mice were harvested and the lung wet/dry weight ratio (W/D) and the pulmonary water contents were measured. The pathological changes in lung tissue were observed by hematoxylin and eosin (HE) staining under microscope, and the extent of lung injury was evaluated. The positive expression of vWF which was the marker of endothelial cell injury was observed by immunohistochemistry. The real-time fluorescence quantitative reverse transcription-polymerase chain reaction (RT-PCR) was used to determine the expression level of FIB mRNA in lung tissue. RESULTS: The lung W/D ratio and pulmonary water contents in the histone group were significantly higher than those in the control group [lung W/D ratio: 6.19±0.53 vs. 4.54±0.25, pulmonary water contents: (82.59±2.03)% vs. (78.52±1.51)%, both P < 0.01]. The lung W/D ratio and pulmonary water contents in the histone+heparin group were significantly lower than those in the histone group [lung W/D ratio: 4.84±0.35 vs. 6.19±0.53, pulmonary water contents: (79.21±1.48)% vs. (82.59±2.03)%, both P < 0.01], indicating that the heparin could reduce histone-induced pulmonary edema. Histological examination showed that the alveolar structure of the control group was intact, and the alveolar cavity was clean without exudation. In the histone group, the lungs were significantly damaged. The alveolar wall was thickened, infiltrated by inflammatory cells and focally alveolar hemorrhage, edema, associated with alveolar fibrin deposition and micro-thrombus formation. The lung histopathological score in the histone group was significantly higher than that in the control group (5.15±0.87 vs. 0.18±0.17, P < 0.01). All of the pathological changes were significantly alleviated in the histone+heparin group, and the histopathological score of the lung was significantly lower than that in the histone group (2.28±0.72 vs. 5.15±0.87, P < 0.01), indicating that the histone-induced lung injury was improved by heparin. Immunohistochemistry showed that high vWF expressions of lung tissue were observed in the histone group while there was almost no positive expression in the control group, and the vWF expression in the histone+heparin group was significantly reduced, indicating that heparin protected mice against histone-induced endothelial cell injury. The FIB mRNA expression of lung tissue in the histone group was about 49.82 times of the control group (2^-ΔΔCT: 55.30±18.84 vs. 1.11±0.45, P < 0.01), and the expression of FIB mRNA in the histone+heparin group was decreased, which was 23.87 times of the control group (2^-ΔΔCT: 26.50±9.97 vs. 1.11±0.45, P < 0.01), but it was significantly lower than that in the histone group (2^-ΔΔCT: 26.50±9.97 vs. 55.30±18.84, P < 0.01), indicating that heparin could inhibit histone-induced hypercoagulable environment in lung. CONCLUSIONS Histone causes pulmonary edema, endothelial cell injury and coagulation activation. Heparin could effectively attenuate histone-induced lung injury and coagulation activation.
Animals ; Fibrinogen/metabolism* ; Fibrinolytic Agents/therapeutic use* ; Heparin/therapeutic use* ; Histones ; Lung/metabolism* ; Male ; Mice ; Mice, Inbred C57BL ; von Willebrand Factor/metabolism*

Von Willebrand factor (vWF) is a glycoprotein with a crucial role in the formation of platelet thrombi, and ADAMTS13 is the main enzyme responsible for vWF cleavage. Both are important in the relationship between diabetic nephropathy, hypercoagulability, and cardiovascular disease. This study evaluated a potential relationship between vitamin D (vitD) levels, vWF, ADAMTS13 activity, and inflammation in diabetic patients on chronic hemodialysis (HD). Blood samples from 52 diabetic patients on chronic HD were obtained to determine vitD levels, vWF, and ADAMTS13 activity, and inflammatory markers. HD patients were grouped according to 25-hydroxyvitamin D [25(OH) VitD]<25 nmol/L (n=16) or >25 nmol/L (n=36). vWF antigen and vWF activity were elevated in both groups, with an average of 214.3±82.6% and 175.8±72.6%, respectively. Average ADAMTS13 activity was within the normal range in both groups. Blood samples from the vitD <25 nmol/L group showed a positive correlation between c-reactive protein (CRP) and vWF levels (P=0.023; r=0.564; 95% confidence interval=0.095-0.828), with a negative correlation between HbA1c and 25(OH) VitD (P=0.015; r=-0.337; 95% confidence interval=-0.337-0.19). Diabetic patients on chronic HD had elevated vWF levels and activity with no significant change in ADAMTS13 activity. The correlation between CRP and vWF levels in the 25(OH) VitD<25 nmol/L group suggests inflammatory-related endothelial dysfunction in these patients.
ADAMTS13 Protein/*metabolism ; Aged ; C-Reactive Protein/analysis ; Diabetes Mellitus, Type 2/complications/*diagnosis/metabolism ; Female ; Hemoglobin A, Glycosylated/analysis ; Humans ; Male ; Middle Aged ; Renal Dialysis ; Renal Insufficiency, Chronic/complications/*diagnosis/metabolism ; Vitamin D/*analogs & derivatives/blood ; von Willebrand Factor/*metabolism

OBJECTIVETo explore effects of Tongxinluo Capsule (TC) on platelet activating factor (PAF), vascular endothelial function, thrombolysis in myocardial infarction (TIMI) blood flow, and heart function in acute myocardial infarction (AMI) patients after delayed percutaneous coronary intervention (PCI).

METHODSTotally 80 AMI inpatients were recruited at Department of Cardiology, People's Hospital of Jiangxi Province, from Jan. 2008 to Sep.2013. Those in line with inclusion criteria were randomly assigned to TC treatment group and the conventional treatment group by random digit table, 40 in each group. Besides, another 40 healthy subjects from examinees at Outpatient Department were recruited as a healthy control group. PCI was performed after 1-week treatment. Then blood samples were collected, and then blood contents of CD62P, CD63, GP II b/III a, ET-1, NO, and plasma von Willebrand factor (vWF) levels were detected. Coronary TIMI blood flow and corrected TIMI frame count (CTFC) were determined during PCI. Meanwhile, noninvasive blood pressure (BP) and heart rate (HR) were recorded before and after PCI, and cardiac function measured. They were compared with the healty control group.

RESULTSCompared with the healthy control group, blood contents of CD62p, CD63, GP II b/IIIa receptor compound, vWF, and ET-1 significantly increased, but NO significantly decreased in AMI patients (all P < 0.05). After 1-week intervention of TC, blood contents of CD62p, CD63, GP II b/IIIa receptor compound, vWF, NO, and ET-1 significantly decreased (P < 0.05, P < 0.01). Compared with the conventional treatment group at the same time point, blood contents of CD62p, CD63, GP II b/IIIa receptor compound, vWF, and ET-1 decreased more significantly in the TC group (P < 0.05, P < 0.01), increased NO levels were also more obviously seen (P < 0.01). The aforesaid parameters changed more obviously at day 30, as compared with those changes at week 1 (P < 0.05, P < 0.01). The TIMI blood flow grade and CTFC were more obviously improved after PCI in the two treatment groups. Better TIMI blood flow was seen in the TC group. TIMI level 3 blood flow rate was higher in the TC group than in the conventional treatment group with statistical difference (P < 0.05). The left ventricular ejective factor (LVEF) after PCI was obviously elevated in the TC group and the conventional treatment group (P < 0.01), and the improvement was more obviously seen in the TC group (P < 0.05). There were 6 cases of recurrent angina, 3 cases of ventricular tachycardial (VT)/ventricular fibrillation (VF), 6 cases of heart failure (HF), 1 case of cardiac sudden death in the conventional treatment group, with the total incidence of cardiovascular events being 40% (16/40). There were 2 cases of recurrent angina, 2 cases of VT/VF, 2 cases of HF, no cardiac sudden death in the TC treatment group, with the total incidence of cardiovascular events being 15% (6/40). There was statistical difference in the recurrent rate of cardiovascular events between the two groups (χ² = 2.27, P < 0.05).

CONCLUSIONTC not only could prevent coronary embolism of AMI patients after delayed PCI, attenuate vascular endothelial injury, but also could improve TIMI blood flow, and strengthen cardiac systolic function.

Angioplasty, Balloon, Coronary ; Blood Pressure ; Drugs, Chinese Herbal ; therapeutic use ; Endothelium, Vascular ; drug effects ; Fibrinolytic Agents ; therapeutic use ; Heart ; drug effects ; Heart Rate ; Humans ; Myocardial Infarction ; drug therapy ; surgery ; Percutaneous Coronary Intervention ; Platelet Activating Factor ; metabolism ; Regional Blood Flow ; von Willebrand Factor ; metabolism

OBJECTIVETo explore the influence of precondintioning on ADAMTS-13 activity and vWF level, and its clinical significance by measuring the alterations of ADAMTS-13 activity and vWF antigen levels before and after preconditioning of hematopoietic stem cell transplantation (HSCT) in the patients.

METHODA total of 113 patients received HSCT in the First Hospital affiliated to Soochow University were investigated, 20 healthy volunteers were used as the control. The ADAMTS-13 activity and vWF antigen level were measured by FRETS-vWF73 and ELISA respectively. Modified BU/CY, TBI/CY or BEAM were used as preconditioning regimen.

RESULTS(1) out of all the patients enrolled in this study, 8 patients were diagnosed as thrombotic disorders, and 49 patients were with occurence of acute graft-versus-host disease (aGVHD); (2) comparing with the control group, the ADAMTS-13 activity were lower and vWF antigen was higher in the patients after preconditioning (P < 0.01). Among all the patients, 69 (59.3%) cases showed the decrease of ADAMTS-13 activity after preconditioning, including 9 patients with more than 60% (9/113, 8.0%) decrease, in the meantime, the average plasma vWF antigen level of these 69 patients was significantly increased after preconditioning (P < 0.05); (3) the plasma ADAMTS-13 activity in 8 patients with thrombotic complications decreased after preconditioning, and there was significant difference in comparision with that of patients without thrombotic complication (P < 0.01). The patients with decrease of ADAMTS-13 activity more than 60% accounted for 37.5% (3/8), at the same time, the the level of vWF antigen increased (P < 0.01); (4) The medium level of ADAMTS-13 activity was dropped in 49 patients with aGVHD after preconditoning, but there was no abvious difference in comparision with that of patients without aGVHD. Among them 25 patients were with significant drop actvity of ADAMTS-13 at that time when aGVHD occurred (P < 0.01). Out of them, the patients with drop more than 60% before preconditioning accounted for 60% (2/35). The logistic regression analyse showed that the drop of ADAMTS-13 activity more than 60% before preconditioning was the risk factor for occurence of thrombosis at the later stage (P < 0.01), but the drop of ADAMTS-13 activity after preconditioning did not was the risk factor for occurence of aGVHD.

CONCLUSIONThe decrease of ADAMTS-13 activity after preconditioning of HSCT confirmed to be lower than that befor preconditioning of HSCT, and the level of vWF antigen after preconditioning of HSCT could be higher than that before precondifioning, especially in patients with thrombosis. The decrease of ADAMTS-13 activity after preconditioning has been found to be mone than 60%, then this decrease can be considered as an independent risk factor for later thrombogenesis, but the decrease of ADAMTS-13 after precoditioning activity did not associate with occurence of aGVHD, so the decrease of ADAMTS-13 activity can be used as an important predictor of thrombosis after HSCT.

ADAM Proteins ; metabolism ; ADAMTS13 Protein ; Case-Control Studies ; Graft vs Host Disease ; diagnosis ; pathology ; Hematopoietic Stem Cell Transplantation ; Humans ; Risk Factors ; Thrombosis ; diagnosis ; pathology ; Transplantation Conditioning ; von Willebrand Factor ; metabolism

Humans ; Isoantibodies ; von Willebrand Factor ; metabolism