OBJECTIVE: To explore the effects of Ena/VASP gene family on the expression of glycoprotein (GP) Ib-IX complex in human megakaryoblastic leukemia Dami cells. METHODS: SiRNAs targeting Ena/VASP gene family were designed and synthesized to interfere Enah, EVL and VASP gene expression. When the siRNAs were transfected into Dami cells by using Lipofectamine^TM 2000 for 48 h, the expression of GPIb-IX complex was detected by quantitative real-time PCR, Western blot and flow cytometry. RESULTS: We successfully established siVASP , siEVL and si Enah Dami cell lines. And it was found that the expression of GPIb-IX complex had no evident reduction in siEVL or siVASP Dami cells at both mRNA and protein level, while the total protein and membrane protein of GPIb-IX complex were obviously reduced when Enah was knocked down. CONCLUSION Enah could affect the expression of GPIb-IX complex in human megakaryoblastic leukemia Dami cells, but the underlying mechanism still needs to be further explored.
Humans ; Cell Line ; Platelet Glycoprotein GPIb-IX Complex/metabolism* ; Leukemia/metabolism* ; Blood Platelets/metabolism*

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*

The Sepsis Coagulopathy Asahi Recombinant LE Thrombomodulin (SCARLET) trial has many defects, and thus cannot be the terminator of recombinant thrombomodulin (rTM). On the contrary, it provides sufficient evidence for further research. Based on analysis focusing on the failure of SCARLET and several previous anticoagulant studies, it is most important for new studies to grasp the following two points: (1) The enrolled cases should have sufficient disease severity and a clear standard for disseminated intravascular coagulation; (2) Heparin should not be used in combination with the investigated drugs. Multiple post-hoc analyses show that no combination of heparin will not increase the risk of thromboembolism. In fact, the combination of heparin can mask the true efficacy of the investigated drug. Due to the complexity of sepsis treatment and the limitations of clinical studies, the results of all treatment studies should be repeatedly verified, rather than be determined at one stroke. Some research conclusions contrary to disease physiology, pharmacology and clinical practice may be deceptive, and should be cautious rather than be simply accepted. On the other hand, the dissenting voices in the "consensus" scene are often well discussed by the authors and should be highly valued.
Humans ; Anticoagulants/therapeutic use* ; Thrombomodulin/therapeutic use* ; Blood Coagulation Disorders ; Disseminated Intravascular Coagulation/drug therapy* ; Sepsis/drug therapy* ; Heparin/therapeutic use* ; Recombinant Proteins

Carcinoma-associated fibroblasts (CAFs) are the main cellular components of the tumor microenvironment and promote cancer progression by modifying the extracellular matrix (ECM). The tumor-associated ECM is characterized by collagen crosslinking catalyzed by lysyl oxidase (LOX). Small extracellular vesicles (sEVs) mediate cell-cell communication. However, the interactions between sEVs and the ECM remain unclear. Here, we demonstrated that sEVs released from oral squamous cell carcinoma (OSCC)-derived CAFs induce collagen crosslinking, thereby promoting epithelial-mesenchymal transition (EMT). CAF sEVs preferably bound to the ECM rather than being taken up by fibroblasts and induced collagen crosslinking, and a LOX inhibitor or blocking antibody suppressed this effect. Active LOX (αLOX), but not the LOX precursor, was enriched in CAF sEVs and interacted with periostin, fibronectin, and bone morphogenetic protein-1 on the surface of sEVs. CAF sEV-associated integrin α2β1 mediated the binding of CAF sEVs to collagen I, and blocking integrin α2β1 inhibited collagen crosslinking by interfering with CAF sEV binding to collagen I. CAF sEV-induced collagen crosslinking promoted the EMT of OSCC through FAK/paxillin/YAP pathway. Taken together, these findings reveal a novel role of CAF sEVs in tumor ECM remodeling, suggesting a critical mechanism for CAF-induced EMT of cancer cells.
Humans ; Paxillin/metabolism* ; Protein-Lysine 6-Oxidase/metabolism* ; Carcinoma, Squamous Cell/pathology* ; Epithelial-Mesenchymal Transition ; Integrin alpha2beta1/metabolism* ; Mouth Neoplasms/pathology* ; Collagen/metabolism* ; Fibroblasts ; Extracellular Vesicles/metabolism* ; Cell Line, Tumor ; Tumor Microenvironment

Thromboembolism is a crucial part of the global disease burden. It has high incidence, high mortality and disability rates, and the mechanism of occurrence and development is extremely complex. It is difficult to detect the disease in the early stage so that we have trouble with clinical prevention and treatment in general. At present, four items of blood coagulation and D-dimer have been widely used in the evaluation and auxiliary diagnosis of thromboembolism, the monitoring of effect for antithrombotic drugs and other fields. The thrombus biomarkers including thrombin-antithrombin complex (TAT), thrombomodulin (TM), tissue plasminogen activator-inhibitor complex (t-PAIC) and α2-plasmin inhibitor-plasmin complex (PIC) fill the gap of laboratory diagnosis before clinical symptoms appear in some degree. This article aims to explain the current application status of TAT, TM, t-PAIC and PIC in thromboembolism and explore their potential application value, so as to provide a reference for selecting appropriate early monitoring indicators for high-risk population of thromboembolism.
Humans ; Tissue Plasminogen Activator ; Plasminogen Inactivators ; Thrombomodulin ; Thromboembolism ; Biomarkers

Thromboembolism is a crucial part of the global disease burden. It has high incidence, high mortality and disability rates, and the mechanism of occurrence and development is extremely complex. It is difficult to detect the disease in the early stage so that we have trouble with clinical prevention and treatment in general. At present, four items of blood coagulation and D-dimer have been widely used in the evaluation and auxiliary diagnosis of thromboembolism, the monitoring of effect for antithrombotic drugs and other fields. The thrombus biomarkers including thrombin-antithrombin complex (TAT), thrombomodulin (TM), tissue plasminogen activator-inhibitor complex (t-PAIC) and α2-plasmin inhibitor-plasmin complex (PIC) fill the gap of laboratory diagnosis before clinical symptoms appear in some degree. This article aims to explain the current application status of TAT, TM, t-PAIC and PIC in thromboembolism and explore their potential application value, so as to provide a reference for selecting appropriate early monitoring indicators for high-risk population of thromboembolism.
Humans ; Tissue Plasminogen Activator ; Plasminogen Inactivators ; Thrombomodulin ; Thromboembolism ; Biomarkers

OBJECTIVE: To investigate the effect of thrombospondin-1 (TSP-1) on apoptosis of human megakaryocytic leukemia cell line Meg-01 and its possible mechanism. METHODS: The expression of CD36 antigen in Meg-01 cells was detected by flow cytometry and immunocytochemistry. Meg-01 cells were cultured for 48 hours with TSP-1 and CD36 antibody FA6-152 at different concentrations. The early apoptosis and activity of caspase-3 were detected by flow cytometry. The effect of TSP-1 on the growth and differentiation of megakaryocytes was investigated by cell counting and CFU-MK culture. RESULTS: The flow cytometry and immunocytochemistry showed that CD36 antigen was expressed on the surface of Meg-01 cells. TSP-1 (5 μg/ml) inhibited the growth of Meg-01 cells, but had unobvious effect on M-07e cells. After addition of CD36 antibody FA6-152 (5, 10, and 25 μg/ml), the inhibition effect of TSP-1 was significantly reduced. TSP-1 (2.5, 5, and 7.5 μg/ml) increased the positive expression of Annexin V (P<0.01) and caspase-3 activity (P<0.01), which indicated that TSP-1 had a significant effect on inducing apoptosis. After addition of CD36 antibody FA6-152 (25 μg/ml), the apoptosis induced by TSP-1 in Meg-01 cells was significantly reduced. TSP-1 (5, 10, and 25 μg/ml) could significantly inhibit the formation of CFU-MK in mouse bone marrow cells, while β-TG could not. CD36 antibody FA6-152 (25 μg/ml) could significantly reduce the inhibition of TSP-1 on CFU-MK. CONCLUSION TSP-1 may induce apoptosis of megakaryocytic leukemia cell line Meg-01 cells via CD36/caspase-3, which provides a potential new drug development and treatment target for clinical treatment of megakaryocytic leukemia.
Animals ; Apoptosis ; CD36 Antigens/metabolism* ; Caspase 3/metabolism* ; Cell Line ; Humans ; Leukemia, Megakaryoblastic, Acute ; Mice ; Thrombospondin 1/pharmacology*

OBJECTIVE: To examine the antiplatelet and antithrombotic activity of Rumex acetosella extract. METHODS: Standard light aggregometry was used for platelet aggregation, intracellular calcium mobilization assessed using Fura-2/AM, granule secretion (ATP release) by luminometer, and fibrinogen binding to integrin α_IIbβ₃ detected using flow cytometry. Western blotting is carried out to determine the phosphorylation of mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K)/Akt signaling. RESULTS: Rumex acetosella displayed the ability to inhibit platelet aggregation, calcium mobilization, granule secretion, and fibrinogen binding to integrin α_IIbβ₃. Rumex acetosella has also down-regulated MAPK and PI3K/Akt phosphorylation (all P<0.01). CONCLUSION Rumex acetosella extract exhibits antiplatelet activity via modulating GPVI signaling, and it may protect against the development of platelet-related cardiovascular diseases.
Blood Platelets/metabolism* ; Calcium/metabolism* ; Fibrinogen/metabolism* ; Mitogen-Activated Protein Kinases/metabolism* ; Phosphatidylinositol 3-Kinase/pharmacology* ; Phosphatidylinositol 3-Kinases/metabolism* ; Phosphorylation ; Plant Extracts/pharmacology* ; Platelet Aggregation ; Platelet Aggregation Inhibitors/pharmacology* ; Platelet Glycoprotein GPIIb-IIIa Complex/pharmacology* ; Proto-Oncogene Proteins c-akt/metabolism* ; Rumex/metabolism*

OBJECTIVE: To analysis the specific protein markers of essential thrombocythemia (ET) based on proteomics technology, to explore and verify the differential protein related to platelet activation. METHODS: Blood samples were obtained from ET patients and healthy people and a certain protein mass spectrometry was detected using label-free quantitative technology. The proteins relative abundance increased or down-regulated by 1.3 times in the disease group compared with the control group, and the protein abundance in the two groups t test P＜0.05 were defined as differential proteins. Bioinformatics analysis of the differential proteins was performed using GO and KEGG. The difference in the average protein abundance between the two groups was analyzed by t test and P＜0.05 was considered statistically significant. Differential proteins were selected for verification by parallel reaction monitoring (PRM) technology. RESULTS: A total of 140 differential proteins were found, of which 72 were up-regulated and 68 were down-regulated. KEGG enrichment showed that the differential protein expression was related to the platelet activation pathway. The differential proteins related to platelet activation were GPV, COL1A2, GP1bα, COL1A1 and GPVI. Among them, the expressions of GPV, GP1bα and GPVI were up-regulated, and the expressions of COL1A2 and COL1A1 were down-regulated. PRM verification of COL1A1, GP1bα, GPVI and GPV was consistent with LFP proteomics testing. CONCLUSION Differential proteins in ET patients are related to platelet activation pathway activation.Differential proteins such as GPV, GPVI, COL1A1 and GP1bα can be used as new targets related to ET platelet activation.
Blood Platelets/metabolism* ; Humans ; Platelet Activation ; Platelet Membrane Glycoproteins/metabolism* ; Technology ; Thrombocythemia, Essential

OBJECTIVE: To analyze the molecular polymorphisms of CD36 among 58 blood donors with CD36 deficiency and compare with CD36 positive controls. METHODS: A total of 58 donors with CD36 deficiency during a screening conducted in the laboratory from September 2019 to December 2020 were enrolled as the test group, including 39 males and 19 females, while 120 platelet donors with CD36 positive were randomly selected as the controls, including 76 males and 44 females. All of the subjects were Han nationality. The PCR-SBT method was used to detect coding region of CD36 gene, and molecular mutations were compared with those CD36 positive controls. RESULTS: Among the 58 donors with CD36 deficiency, mutations appears in 32 individuals. The detection rate for type I was 71.43% (5/7), and type II was 51.92% (27/52), while among the 120 controls, mutations appears in 12 donors (10%). In the CD36 antigen-deficient donors, 16 variations were found, in which 329-330 del AC with the highest frequency accounted for 20.69%, followed by 1228-1239 del ATTGTGCCTATT(15.52%) and 1156 C>T(10.34%). Two variations, 198-205 del GATCTTTG and 220 C>T, led to premature termination of translation; four mutations, 329-330 del AC, 560 ins T, 1011-1049 39bp dupl and 1343-1344 ins TCTT, caused translation frame shift; 1228-1239 del ATTGTGCCTATT led to deletion of four amino acids (Ile-Val-Pro-Ile) at sites 410-413 of the peptide chain. The 1140 T>A and 1275 G>A were synonymous mutations, and the other 7 mutations resulted in the substitution of single nucleotide. The platelet expression in the donors of CD36 positive with 329-330 del AC or 1228-1239 del ATTGTGCCTATT mutation (heterozygote) was lower than those CD36 positive individuals without mutations (homozygote). CONCLUSION Multiple gene mutations in the CD36 coding region may cause CD36 deficiency, and the heterozygous individuals with mutations may lead to CD36 antigen reduction or deletion. Mutation is not detected in 44.83% of CD36 deficient individuals, there may be some other reasons for the CD36 antigen deficiency.
Blood Donors ; Blood Platelet Disorders/metabolism* ; Blood Platelets/metabolism* ; CD36 Antigens/metabolism* ; Female ; Genetic Diseases, Inborn ; Humans ; Male