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

AIMTo study the antagonistic effect of myricetin on platelet activing factor (PAF).

METHODSThe specific binding of [3H] PAF to rabbit platelet receptor was investigated using radio ligand binding assay (RLBA). Platelet adhesion induced by PAF was measured with spectrophotometry. The elevation of inner free calcium concentration in rabbit polymorphonuclear leukocytes (PMNs) induced by PAF was assayed by Fura-2 fluorescent technique.

RESULTSThe specific binding inhibition potency of Myr was found to be concentration-dependent. The IC50 of Myr in [3H] PAF 1, 2 and 4 nmol.L-1 were 34.8, 85.7 and 118.6 mumol.L-1, respectively. The PAF induced reactions of rabbit platelet adhesion and PMNs inner free calcium concentration increase were inhibited by Myr in a dose-dependent manner. The IC50 of Myr to inhibit platelet adhesion was 13.1 mumol.L-1.

CONCLUSIONThe specific receptor binding of PAF can be antagonized by myricetin.

Animals ; Calcium ; metabolism ; Flavonoids ; pharmacology ; Male ; Neutrophils ; metabolism ; Platelet Activating Factor ; antagonists & inhibitors ; metabolism ; Platelet Activation ; drug effects ; Platelet Adhesiveness ; drug effects ; Platelet Aggregation Inhibitors ; pharmacology ; Platelet Membrane Glycoproteins ; metabolism ; Rabbits ; Receptors, G-Protein-Coupled ; metabolism

OBJECTIVESTo study the interaction of beta-2-glycoprotein I (beta 2GPI) with the membrane of hepatocytes and determine whether beta 2GPI participates in HBV infection.

METHODSLigand blotting, fluorescence microscopy, and fluorescence activated cell sorter (FACS) analysis were used to detect the specific interaction of beta 2GPI with the hepatoma cell line smmc7721, the gastric carcinoma cell line SGC7901, and the lymphoma cell line HL-60.

RESULTSA specific 40 kDa beta 2GPI band was observed by ligand blotting in the case of smmc7721 cells. No such band was observed in SGC7901 or HL-60 cells. Fluorescence microscopy also revealed specific binding of FITC-beta 2GPI to smmc7721 cells, but neither to SGC7901 nor HL-60 cells. FACS analysis demonstrated that the binding rate of FITC-beta 2GPI to smmc7721 cells was significantly higher than these in SGC7901 and HL-60 cells (P < 0.01). The binding rate to smmc7721 cells did not increase with increasing amounts of FITC-beta 2GPI.

CONCLUSIONSThere is a specific beta 2GPI-binding protein on the membrane of hepatoma cells in cell line smmc7721 which as the beta 2GPI receptor may participate in HBV infection of hepatocytes.

Animals ; Carcinoma, Hepatocellular ; Cell Membrane ; metabolism ; Flow Cytometry ; Glycoproteins ; metabolism ; Hepatocytes ; metabolism ; Liver Neoplasms, Experimental ; metabolism ; Platelet Glycoprotein GPIb-IX Complex ; analysis ; Platelet Membrane Glycoproteins ; Tumor Cells, Cultured ; beta 2-Glycoprotein I

Platelet glycoprotein VI (GPVI) is a major receptor for collagen on the platelet surface. It mediates the initial platelet contact with collagen, generates intracellular signals, increases the affinity of integrin receptor, and causes platelet aggregation and thrombosis. Suppression of GPVI function can significantly inhibit collagen-induced platelet adhesion, aggregation and thrombosis, so GPVI has become a novel target for antiplatelet therapy. Within the last few years, major advances have been made in understanding platelet-collagen interactions. In this paper, the advances of study on GPVI, including composition of GPVI, functions of GPVI, factors related with functions of GPVI, GPVI and clinic were summarized.
Humans ; Platelet Adhesiveness ; physiology ; Platelet Aggregation ; physiology ; Platelet Glycoprotein GPIIb-IIIa Complex ; metabolism ; physiology ; Platelet Glycoprotein GPIb-IX Complex ; metabolism ; physiology ; Platelet Membrane Glycoproteins ; chemistry ; metabolism ; physiology ; Protein Binding ; physiology

Changes in microparticles (MP) from red blood cell (RBC) concentrates in the context of irradiation have not been investigated. The aim of this study was to evaluate how irradiation affects the number of MPs within transfusion components. Twenty RBC concentrates, within 14 days after donation, were exposed to gamma rays (dose rate: 25 cGy) from a cesium-137 irradiator. Flow cytometry was used to determine the numbers of MPs derived from RBC concentrates before and 24 hr after irradiation. The mean number of MPs (±standard deviation) in RBC concentrates was 21.9×10(9)/L (±22.7×10(9)/L), and the total number of MPs ranged from 2.6×10(9)/L to 96.9×10(9)/L. The mean number of MPs increased to 22.6×10(9)/L (±31.6×10(9)/L) after irradiation. Before irradiation, the CD41-positive and CD235a-positive MPs constituted 9.5% (1.0×10(9)/L) and 2.2% (263×10(6)/L) of total MPs, respectively. After irradiation, CD41-positive MPs increased to 12.1% (1.5×10(9)/L) (P=0.014), but the CD235a-positive MPs decreased to 2.0% (214×10(6)/L) of the total MPs (P=0.369). Irradiation increases the number of CD41-positive MPs within RBC concentrates, suggesting the irradiation of RBC concentrates could be associated with thrombotic risk of circulating blood through the numerical change.
Cell-Derived Microparticles/chemistry/*metabolism/radiation effects ; Erythrocytes/*cytology/radiation effects ; Flow Cytometry ; Gamma Rays ; Humans ; Membrane Glycoproteins/metabolism ; Metalloendopeptidases/metabolism ; Platelet Membrane Glycoprotein IIb/metabolism

OBJECTIVETo study the pathological and clinical characteristics of a patient with spontaneous platelet aggregation of his giant and morphologically abnormal platelets.

METHODSPlatelet size and structure were observed under light microscope and electron microscope. Platelet aggregation was measured turbidometrically. Platelet glycoproteins (GP) were analyzed using flow cytometry. PCR and DNA sequencing were performed to identify the gene abnormality.

RESULTSThe patient had spontaneous platelet aggregation of giant platelets with thickened plasma membrane and increased number of granules in various shapes. Aspirin and ticlopidine did not affect the spontaneous aggregation. The expression of GP I b, GP II b, GP III a and P-selectin in the platelet membrane were in normal range. Results of gene analyses for GP I balpha, GP I bbeta and GPIX were also normal.

CONCLUSIONBoth morphological and functional abnormalities of the platelets from the patient were clearly distinguishable from that of other hereditary giant platelet disorders. It would probably represent a novel platelet disorder which had not been reported to date.

Aspirin ; pharmacology ; Bernard-Soulier Syndrome ; metabolism ; pathology ; Blood Platelet Disorders ; metabolism ; pathology ; Cell Size ; physiology ; Child ; Cytoplasmic Granules ; pathology ; ultrastructure ; Female ; Humans ; Platelet Aggregation ; drug effects ; physiology ; Platelet Aggregation Inhibitors ; pharmacology ; Platelet Membrane Glycoproteins ; genetics ; metabolism ; Ticlopidine ; pharmacology

OBJECTIVETo observe the platelet activating factor (PAF) antagonistic effect of kaempferol.

METHODThe specific binding of [3H] PAF to rabbit platelet receptor was investigatedwith radio ligand binding assay (RLBA). Platelet adhesion induced by PAF was measured with spectrophotometry. The elevation of inner free calcium concentration in rabbit polymorphonuclear leukocytes (PMNs) induced by PAF was determined with Fura-2 fluorescent technique.

RESULTThe 1, 2 or 4 nmol x L(-1) [3H]PAF specific binding to rabbit platelet receptor was inhibited by Kae dosage dependently and the IC50 were 30.8, 74.6 and 92.0 micro mol x L(-1), respectively. The PAF induced reactions of rabbit platelet adhesion and PMNs inner free calcium concentration elevation were inhibited by Kae in a dose-dependent manner. The IC50 of Kae to inhibit platelet adhesion was 65 micromol x L(-1).

CONCLUSIONKae is effective in inhibiting the action of PAF and it is a new PAF receptor antagonist.

Animals ; Blood Platelets ; drug effects ; physiology ; Calcium ; metabolism ; Kaempferols ; pharmacology ; Male ; Neutrophils ; metabolism ; Platelet Activating Factor ; metabolism ; Platelet Adhesiveness ; drug effects ; Platelet Membrane Glycoproteins ; antagonists & inhibitors ; metabolism ; Rabbits ; Radioligand Assay ; Receptors, G-Protein-Coupled ; antagonists & inhibitors ; metabolism

This study was purposed to explore the influence of S-nitrosoglutathione (GSNO) on membrane glycoprotein of frozen platelet. The levels of membrane glycoprotein on fresh liquid platelets, frozen platelets and frozen platelets with GSNO were measured by flow cytometry. The results showed that the GSNO obviously decreased platelet aggregation, the PAC-1 change in the three groups was not significant. The changes of CD42b and CD62P in fresh liquid platelet group, frozen platelet group and frozen platelets with GSNO were significant different. The change of membrane glycoprotein in above-mentioned three group was not significant. It is concluded that the GSNO inhibits platelet aggregation, maintains the function of platelets and may be used as a cryoprotectant. When frozen platelets were added with GSNO, the molecular rearrangement, structure change and other mechanism may occur in platelets.
Blood Platelets ; drug effects ; Blood Preservation ; methods ; Freezing ; Humans ; P-Selectin ; metabolism ; Platelet Activation ; drug effects ; Platelet Glycoprotein GPIb-IX Complex ; metabolism ; Platelet Membrane Glycoproteins ; metabolism ; S-Nitrosoglutathione ; pharmacology

OBJECTIVEThis study aimed to investigate the roles of platelet activating factor (PAF) receptor antagonist in damage to intestinal mucin-2 (MUC2) during endotoxemia on young rats.

METHODSEighteen-day-old Wistar rats were randomized to be treated with lipopolysaccharide (LPS) (5 mg/kg), LPS plus PAF receptor antagonist and normal saline injection (control). PAF receptor antagonist BN52021 5 mg/kg was administered 30 minutes before or after LPS injection (pretreatment group or treatment group). The ileum specimens (n = 8) were harvested at 1.5, 3, 6, 24, 48 and 72 hours after LPS injection. Transmission electron microscopy was used for morphologic evaluation. Immunohistochemistry was used to determine MUC2 in intestinal mucosa.

RESULTSMicrovilli and tight junctions were intact in the control group. Enlargement of tight junctions were seen in the LPS group and microvilli were thin, rare or disrupted, shed. The rough endoplasmic reticulum, mitochondria, and glycogen particles were injured. The changes of the pretreatment and treatment group were slightly milder than that in the LPS group. Ileum of a control rat in which a thin layer of mucus covering the epithelial surface and mucin-containing goblet cells appeared very distended. The experiment group showed a decrease or irregularly distributed membranous mucus expression. The MUC2 content of absorbance significantly decreased in the LPS challenged group compared with that in the control group (P < 0.01), and reached a nadir at 6 hours (0.1841 +/- 0.0047) vs. the control group (0.2091 +/- 0.0060) (P < 0.01). The tendency of the level of MUC2 in the pretreatment and treatment group was the same as that of the LPS group, and the level of MUC2 in the pretreatment and treatment group was higher than that in the LPS group at each time point. ANOVA analysis showed that the inter-group and intra-group difference had statistical significance (P < 0.05).

CONCLUSIONSPAF may play some roles in the injury of intestinal mucus barrier function during endotoxemia. Preventive and remedial use of PAF receptor antagonist BN52021 may relieve intestinal injury.

Animals ; Endotoxemia ; metabolism ; pathology ; Intestinal Mucosa ; drug effects ; metabolism ; pathology ; Mucin-2 ; metabolism ; Platelet Membrane Glycoproteins ; antagonists & inhibitors ; Rats ; Rats, Wistar ; Receptors, G-Protein-Coupled ; antagonists & inhibitors

OBJECTIVETo study the expression of specific anti- platelet glycoprotein autoantibodies GP II b/III a, GP I b/IX and GP I a/II a in primary immune thrombocytopenia (ITP), and to evaluate the relationship between the therapeutic effect and the expression of specific anti- platelet glycoprotein antibodies GPIIb/IIIa, GPIb/IX and GPIa/IIa.

METHODSAnti-GPIIb/IIIa, GPIb/ IX and GP I a/II a antibodies were assayed by ELISA for patients with ITP. Total 442 patients in our hospital, who were retrospectively investigated from December 2010 to November 2012, were divided into newly diagnosed ITP, persistent and chronic ITP. The expression of specific anti- platelet glycoprotein antibody in each group was measured separately. The newly diagnosed ITP patients were treated with intravenous IgG (IVIG) and corticosteroids. The relationship between the expression of specific anti- platelet glycoprotein antibodies GPIIb/IIIa, GPIb/IX and GPIa/IIa and the complete response (CR) was studied.

RESULTSPositive rates of anti- platelet glycoprotein antibodies were 59.09%, 26.97% and 37.35% respectively in newly diagnosed ITP, persistent and chronic ITP, the difference was statistical significant (P<0.05). In newly diagnosed ITP, positive rate of antibody against GPIIb/IIIa was 38.64%, double positive rate of antibodies against both GP II b/III a and GP I a/II a was 15.91%, there was statistical significance (P<0.05) compared with that of persistent and chronic ITP. The complete response (CR) rate in newly diagnosed ITP patients with positive antibody against GP II b/III a was 80.39% after treatment with IVIG and corticosteroids. There was statistical significance compared with that in patients having no antibodies (P<0.05).

CONCLUSIONThe expression of antibodies against GP II b/III a and double positive for both GP II b/III a and GP I a/II a autoantibodies increased in newly diagnosed ITP patients. Patients with anti-GP II b/III a autoantibody had good response to medication with IVIG and corticosteroids.

Adolescent ; Adult ; Aged ; Autoantibodies ; metabolism ; Child ; Child, Preschool ; Female ; Humans ; Male ; Middle Aged ; Platelet Glycoprotein GPIIb-IIIa Complex ; immunology ; Platelet Glycoprotein GPIb-IX Complex ; immunology ; Platelet Membrane Glycoproteins ; immunology ; Retrospective Studies ; Thrombocytopenia ; drug therapy ; immunology ; metabolism ; Treatment Outcome ; Young Adult