Objective To evaluate whether Vibrio vulnificus secreted exotoxin-hemolysin (VVH) can activate platelet, an important blood immune cell, and to explore the possible molecular mechanism of platelet activation by VVH. Methods Transcriptomics and immunohistochemistry were used to analyze whether Vibrio vulnificus infection caused platelet activation in mice. Then, flow cytometry was used to identify whether VVH was the main stimulator of platelet activation. Naturally expressed VVH toxin was purified and prepared. The effects of extracellular and intracellular Ca²⁺ signal inhibitors on VVH activated platelets were evaluated by flow cytometry and Western blotting. The immune activation effect of VVH in the early stage of Vibrio vulnificus infection was analyzed in vivo. Results VVH was the main stimulator of platelet activation in Vibrio vulnificus culture supernatant. Natural VVH can induce the increase of P-selectin (CD62P) on platelet surface, the formation of platelet-neutrophil complex (PNC), and the release of platelet microvesicles. The activation mechanism may be related to the VVH pore-dependent Ca²⁺-calmodulin (CaM) -myosin light chain kinase (MLCK) signaling pathway, which led to the release of platelet alpha particles and cascade activation of platelets. In a mouse model of ALD infected by Vibrio vulnificus gavage, VVH was strongly associated with platelet activation. Conclusion This study shows that VVH is an important platelet activating molecule in the early stage of Vibrio vulnificus infection, and its induction of platelet activation may be related to the pathogenic process.
Animals ; Platelet Activation/drug effects* ; Hemolysin Proteins/pharmacology* ; Vibrio vulnificus/metabolism* ; Mice ; Blood Platelets/drug effects* ; Vibrio Infections/immunology* ; P-Selectin/metabolism* ; Bacterial Proteins ; Female

OBJECTIVE: To investigate the effects of oridonin on platelet function and related mechanisms. METHODS: Washed platelets from healthy adults and mice were incubated with different concentrations of oridonin (2.5, 5 and 10 μmol/L) in vitro . The surface expression level of P-selectin and the activation of integrin αIIbβ3 in platelets were detected by flow cytometry, and the aggregation ability of platelets under the stimulation by various agonists was detected by light transmission aggregometry. The expression of P-AKT (Ser473) was detected by protein immunoblotting. Arterial thrombosis model was established in mice with mesenteric injury induced by ferric chloride, and tail hemorrhage model was established by cutting off the tail of mice. The effect of intraperitoneal injection of oridonin (10 mg/kg) on thrombosis and haemostasis was tested. RESULTS: Oridonin inhibited platelet P-selectin expression and integrin αIIbβ3 activation. In the presence of different stimulants, oridonin inhibited platelet aggregation in a concentration-dependent manner. The phosphorylation level of AKT Ser473 was reduced in the groups treated with different concentrations of oridonin. Oridonin significantly prolonged the time of mesenteric artery thrombosis in mice, but did not affect the tail bleeding time. CONCLUSION Oridonin inhibits platelet activation, aggregation, and thrombosis by inhibiting AKT phosphorylation, and may be used as a potential antiplatelet drug.
Diterpenes, Kaurane/pharmacology* ; Animals ; Mice ; Blood Platelets/drug effects* ; Platelet Aggregation/drug effects* ; P-Selectin/metabolism* ; Thrombosis ; Platelet Glycoprotein GPIIb-IIIa Complex/metabolism* ; Proto-Oncogene Proteins c-akt/metabolism* ; Humans ; Phosphorylation ; Platelet Activation/drug effects*

OBJECTIVE: To investigate the effect of vitamin D3 to platelet activation by tumor cell culture medium. METHODS: The peripheral blood platelets of BALB/c mice were isolated. The platelets were activated in 4T1 culture fluid for 24 h. The platelets were divided into 7 groups: control group, activation group, 1 nmol/L vitamin D3 group, 10 nmol/L vitamin D3 group, 50 nmol/L vitamin D3 group, 100 nmol/L vitamin D3 group, and positive drug (0.1 μmol/L eptifibatide) group. CCK-8 assay was used to detect the platelet proliferation at 24, 48 and 72 h. Flow cytometry was used to detect the expression of CD61 and CD62p and receptor for advanced glycation end products (RAGE) at 24, 48 and 72 h. ELISA was used to detect the level of platelet-endothelial cell adhesion molecule-1 (PECAM-1) at 24, 48 and 72 h. RESULTS: The CD41 CONCLUSION Vitamin D3 shows antiplatelet effect and can inhibit platelet proliferation and activation.
Animals ; Blood Platelets ; Cell Culture Techniques ; Cholecalciferol/pharmacology* ; Flow Cytometry ; Mice ; Mice, Inbred BALB C ; P-Selectin ; Platelet Activation

OBJECTIVE: To investigate the predictive effect of platelet activation index expression before and after adenosine bisphosphate activation on bleeding risk in patients with primary immune thrombocytopenia (ITP). METHODS: Eighty-nine patients with ITP admitted in our hospital from January 2017 to October 2018 were selected and inrolled in ITP group, the bleeding scoreing and grading were performed by using the ITP-BAT for ITP patients, then 89 ITP patients were divided into 4 subgroups: nothing bleeding symptom group, mild bleeding symprom group, mode rate bleeding symptom group and severe bleeding symptom group according to bleeding scores and grades obtained from ITP-BAT detection. At the same time, 22 persons underwent the health physical examination were selected and enrolled in control group. The adenosine diphosphate (ADP) was used as activator for all patients and controls. The flow cytonetry was used to analyze the expression of platelet membranc glyco protein (GPⅠb, GPⅡb /Ⅲ a) and P-selectin before and after ADP activation, the multiple linear person's correlation analysis was used to analyze the correlation of bleeding degree of ITP patients before and after ADP acbivation with the expression levels of GPⅠb, GPⅡb/Ⅲa and P-selectin. RESULTS: After the ADP activation, the expression level of GPⅠb significantly decreased, while the expression levels of GPⅠb, GPⅡb/Ⅲ a and P-selectin significantly increased in control group, nothing bleeding symptom group and mild bleeding symptom group; but the expression level of GPⅠb significantly increased, while the expression level of GPⅡb/Ⅲ a significantly decreased in moderate and severe bleeding symptom group, the both differences were statistically significant (P＜0.05). however, the expression level of P-selectin in moderate and severe bleeding symptom groups before and after ADP activation was not statistivally significant (P＞0.05). Before ADP activation, the expression level of GPⅠb in ITP subgroups was lower than that in control group, the expression level of GPⅡb/Ⅲ a in ITP subgroups was higher than that in control group, the expression level of P-selectin in moderate and severe bleeding symptom groups was higher than that in control group (P＜0.05). After ADP activation, the expression levels of GPⅠb and P-selectin in ITP subgroups both were lower than those in control group, the expression level of GPⅡb/Ⅲa in ITP subgroups was higher than that in control group (P＜0.05). The comparison among ITP subgroups showed that before ADP activation, the expression level of GPⅠb in moderate and severe bleeding symptom groups was lower than that in nothing bleeding symotom and mild bleeding symptom groups, while the expression levels of GPⅡb/Ⅲa and P-selectin were higher than those in nothing bleeding symptom and mild bleeding symptom groups (P＜0.05), however, after ADP activation, the expression level of GPⅠb in moderate and severe bleeding symptom groups was higher than that in nothing bleeding symptom and mild bleeding symptom groups, while the expression levels of GPⅡb/Ⅲ a and P-selection in moderate and severe bleeding symptom groups were lower than those in nothing and mild bleeding symptom groups (P＜0.05). The correlation analysis showed that before ADP activation, the expression levels of GPⅠb and GPⅡb/Ⅲa positivdy correlated with the bleeding risk (r=0.483, 0.504), and the P-selectin not correlated with the bleeding risk (r=0.000); however, after ADP activation, the expression level of GPⅠb and GPⅡb/Ⅲ a negatively correlated with the bleeding risk (r=-0.627, -0.406, -0.108). CONCLUSION The expression level of platelet activation indicators before and after ADP activation is of certain value for prevention of bleeding risk in ITP patients and can be used as a reference indicator for the treatment and efficacy evaluation.
Adenosine ; Blood Platelets ; Humans ; P-Selectin ; Platelet Activation ; Platelet Count ; Purpura, Thrombocytopenic, Idiopathic

BACKGROUND/AIMS: Although epigallocatechin-3-gallate (EGCG), which is found in high contents in the dried leaves of green tea, has been reported to have an anti-platelet effect, synergistic effects of EGCG in addition to current anti-platelet medications remains to be elucidated. METHODS: Blood samples were obtained from 40 participants who took aspirin (ASA, n = 10), clopidogrel (CPD, n = 10), ticagrelor (TCG, n = 10) and no anti-platelet medication (Control, n = 10). Ex vivo platelet aggregation and adhesion under various stimulators were analyzed by multiple electrode aggregometry (MEA) and Impact-R systems. PAC-1 and P-selectin expressions in human platelets were analyzed by flow cytometry. RESULTS: In MEA analysis, adenosine diphosphate (ADP) and thrombin receptor activating peptide (TRAP)-induced platelet aggregations were lower in the CPD and the TCG groups; arachidonic acid (AA)-induced platelet aggregation was lower in the ASA group, whereas collagen (COL)-induced platelet aggregations were comparable among four groups. EGCG significantly reduced ADP- and COL-induced platelet aggregation in dose-dependent manner (ADP, p = 0.04; COL, p < 0.01). There were no additional suppressions of platelet aggregation stimulated by AA in the ASA group, and by ADP in the CPD and TCG groups. Moreover, EGCG suppressed shear stress-induced platelet adhesion on Impact-R, and had no effect on P-selectin and PAC-1 expressions. CONCLUSIONS: Ex vivo treatment of EGCG inhibited platelet adhesion and aggregation without changes in P-selectin and PAC-1 expression. There was no additional suppressions in platelet aggregation stimulated by AA in the ASA group and ADP in the CPD and TCG groups.
Adenosine Diphosphate ; Arachidonic Acid ; Aspirin* ; Blood Platelets ; Catechin ; Collagen ; Electrodes ; Flow Cytometry ; Humans ; P-Selectin ; Platelet Aggregation ; Platelet Aggregation Inhibitors ; Receptors, Thrombin ; Tea

<p>OBJECTIVETo investigate the coagulation abnormality and tumor-associated hypercoagulable state in lymphoma-bearing mice by measuring the changes in coagulation indices (D-D, vWF, TF) and platelet activation indices (P-selectin, GPIIbIIIa).p><p>METHODSThe mouse model with lymphoma was established by the subcutaneous injection of 38B9 lymphoma cells into BALB/c mice, and the tumor formation was evaluated by using MRI and B ultrasonography. The D-D, vWF and TP levels of blood samples from inner canthal vein of tumor-bearing mice on 1 d, 14 d and 21 d were detected by using ELISA, the platelet activation indices (P-selectin, GPIIbIIIa) were detected by using flow cytometry.p><p>RESULTSThe lymphoma-bearing mouse model was successfully established. The levels of D-D, vWF and TF as well as platelet activation indices P-selectin and GPIIbIIIa in the peripheraI blood were significantly higher than those of control group (P<0.05).p><p>CONCLUSIONLymphoma-bearing mice showed abnormalities of coagulation and platelet activation, which relates with the tumor hypercoagulable state in lymphoma-bearing mice.p>
Animals ; Blood Coagulation ; Lymphoma ; Mice ; Mice, Inbred BALB C ; P-Selectin ; Platelet Activation ; Thrombophilia

<p>OBJECTIVETo study the association between the single nucleotide polymorphisms (SNPs) of the ninth exon Val279Phe of platelet-activating factor acetylhydrolase (PAF-AH) gene and gastrointestinal bleeding in children with Henoch-Schönlein purpura (HSP).p><p>METHODSA total 516 children with HSP were enrolled, among whom 182 had gastrointestinal bleeding and 334 had no gastrointestinal bleeding. PCR was used to investigate the distribution of genotypes and alleles in the SNPs of Val97Phe. The plasma PAF-AH activity was measured, as well as the levels of platelet-activating factor (PAF), granular membrane protein-140 (GMP-140), β-thromboglobulin (β-TG), and platelet factor 4 (PF4).p><p>RESULTSThe Val279Phe genotype and allele frequencies were in Hardy-Weinberg equilibrium, and the homozygous genotype TT and heterozygotes accounted for 0.97% and 6.05% respectively. The gastrointestinal bleeding group had a significantly higher allele frequency than the control group (5.22% vs 3.33%; P<0.01). The HSP patients with GG genotype in the gastrointestinal bleeding group had significantly higher levels of plasma PAF and GMP-140 than those in the non-gastrointestinal bleeding group (P<0.05), while the non-gastrointestinal bleeding group had a significantly higher PAF-AH activity than the gastrointestinal bleeding group (P<0.05). There were no significant differences in β-TG and PF4 between the two groups (P>0.05).p><p>CONCLUSIONSVal279Phe gene polymorphisms in PAF-AH are associated with PAF-AH activity and PAF and GMP-140 levels and may be a risk factor for HSP with gastrointestinal bleeding.p>
1-Alkyl-2-acetylglycerophosphocholine Esterase ; genetics ; Adolescent ; Child ; Child, Preschool ; Female ; Gastrointestinal Hemorrhage ; etiology ; Genotype ; Humans ; Infant ; Male ; P-Selectin ; blood ; Platelet Activating Factor ; analysis ; Polymorphism, Single Nucleotide ; Purpura, Schoenlein-Henoch ; blood ; complications

<p>OBJECTIVETo investigate the effect of ulinastatin (UTI) for early drug intervention on the serum levels of tumor necrosis factor-α (TNF-α), P-selectin, and thrombin-antithrombin complex (TAT) in young rats with sepsis.p><p>METHODSA total of 120 male rats aged 4 weeks were randomly divided into normal control group, sham-operation group, sepsis group, low-dose UTI group (50 000 U/kg), and high-dose UTI group (200 000 U/kg), with 24 rats in each group. Modified cecal ligation and puncture was performed to establish a rat model of sepsis, and the rats in the low- and high-dose UTI groups were given caudal vein injection of UTI after model establishment. ELISA was used to measure the serum levels of TNF-α, P-selectin, and TAT at 6, 12, and 24 hours after model establishment.p><p>RESULTSThe sepsis group had significant increases in the serum levels of TNF-α, P-selectin, and TAT at 6 hours, and the serum levels of TNF-α and TAT continued to increase by 24 hours (P<0.05); P-selectin reached the peak at 12 hours and decreased slightly at 24 hours (P<0.05). The UTI groups had similar change patterns in the levels of P-selectin and TAT as the sepsis group. The UTI groups had significant increases in the level of TNF-α at 6 hours, but gradually decreased over time. The changes in serum levels of TNF-α, P-selectin, and TAT in the UTI groups were significantly smaller than in the sepsis group (P<0.05). The high-dose UTI group had significantly smaller changes in serum levels of TNF-α, P-selectin, and TAT than the low-dose UTI group (P<0.05).p><p>CONCLUSIONSEarly intervention with UTI can significantly improve coagulation function and inhibit the production of TNF-α, P-selectin, and TAT in young rats with sepsis. High-dose UTI has a significantly greater effect than low-dose UTI.p>
Animals ; Antithrombin III ; Glycoproteins ; pharmacology ; therapeutic use ; Male ; P-Selectin ; blood ; Peptide Hydrolases ; blood ; Rats ; Rats, Sprague-Dawley ; Sepsis ; blood ; drug therapy ; Tumor Necrosis Factor-alpha ; blood

<p>OBJECTIVETo study the effect of aqueous extract of several kinds of herbs on human platelet aggregation and expression of P-selectin in vitro.p><p>METHODSBlood was collected from volunteers. Effects of the prepared water extracts of herbs on platelet aggregation were monitored on a Packs-4 aggregometer. The fluorescence intensity of water extracts of Caulis Spatholobi, Flos Carthami and Rhizoma Curcumae on the expression of P-selectin in human platelets of healthy persons was measured with flow cytometry.p><p>RESULTSOut of several herbs investigated, Flos Carthami and Rhizoma Curcumae potently inhibited platelet aggregation after incubation with platelet-rich plasma (PRP) for 15 min. Caulis Spatholobi Flos Carthami and Rhizoma Curcumae inhibited adenosine-5'-diphosphate (ADP) or platelet activating factor (PAF)-induced platelet aggregation in PRP in a dose-dependent manner. In contrast to Flos Carthami and Rhizoma Curcumae, Caulis Spatholobi could not inhibit thrombin-induced platelet aggregation. Despite its inability to inhibit thrombin-induced platelet aggregation in PRP, Caulis Spatholobi had a greater anti-aggregating activity in PRP induced by ADP or PAF. Caulis Spatholobi and Flos Carthami showed significant inhibitory effects on the expression of P-selectin.p><p>CONCLUSIONSCaulis Spatholobi, Flos Carthami and Rhizoma Curcumae have potent anti-platelet properties, and their inhibitory actions are mediated via different mechanisms. Caulis Spatholobi inhibited ADP-induced platelet aggregation but not by thrombin, indicating that its mechanism of action might be independent of the thromboxane pathway. The effect of Caulis Spatholobi and Flos Carthami were associated with suppressing the expression of P-selectin.p>
Adult ; Blood Platelets ; drug effects ; metabolism ; Curcuma ; chemistry ; Fabaceae ; chemistry ; Humans ; P-Selectin ; metabolism ; Plant Extracts ; chemistry ; pharmacology ; Plants, Medicinal ; chemistry ; Platelet Aggregation ; drug effects ; Platelet Function Tests ; Water ; chemistry ; Young Adult

The opening of mitochondrial permeability transition pore (MPTP) plays a critical role in platelet activation. However, the potential trigger of the MPTP opening in platelet activation remains unknown. Inflammation is the crucial trigger of platelet activation. In this study, we aimed to explore whether and how the important inflammatory cytokine IL-17 is associated with MPTP opening in platelets activation by using MPTP inhibitor cyclosporine-A (CsA). The mitochondrial membrane potential (ΔΨm) was detected to reflect MPTP opening levels. And the platelet aggregation, activation, and the primary signaling pathway were also tested. The results showed that the MPTP opening levels were increased and Δψm reduced in platelets administrated with IL-17. Moreover, the levels of aggregation, CD62P, PAC-1, P53 and the phosphorylation of ERK2 were enhanced along with the MPTP opening in platelets pre-stimulated with IL-17. However, CsA attenuated these effects triggered by IL-17. It was suggested that IL-17 could induce MPTP opening through ERK2 and P53 signaling pathway in platelet activation and aggregation.
Blood Platelets ; cytology ; drug effects ; metabolism ; Cell Separation ; Cyclosporine ; pharmacology ; Dual Specificity Phosphatase 2 ; genetics ; metabolism ; Gene Expression Regulation ; Humans ; Interleukin-17 ; metabolism ; pharmacology ; Membrane Potential, Mitochondrial ; drug effects ; Mitochondria ; drug effects ; metabolism ; Mitochondrial Membrane Transport Proteins ; agonists ; antagonists & inhibitors ; genetics ; metabolism ; Mitogen-Activated Protein Kinase 1 ; genetics ; metabolism ; P-Selectin ; genetics ; metabolism ; Phosphorylation ; drug effects ; Platelet Activation ; drug effects ; Platelet Aggregation ; drug effects ; Primary Cell Culture ; Signal Transduction ; Tumor Suppressor Protein p53 ; genetics ; metabolism