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*

The fields of pharmacogenetics and pharmacogenomics have become increasingly promising regarding the clinical application of genetic data to aid in prevention of adverse reactions. Specific screening tests can predict which animals express modified proteins or genetic sequences responsible for adverse effects associated with a drug. Among the genetic variations that have been investigated in dogs, the multidrug resistance gene (MDR) is the best studied. However, other genes such as CYP1A2 and CYP2B11 control the protein syntheses involved in the metabolism of many drugs. In the present study, the MDR-1, CYP1A2 and CYP2B11 genes were examined to identify SNP polymorphisms associated with these genes in the following four canine breeds: Uruguayan Cimarron, Border Collie, Labrador Retriever and German Shepherd. The results revealed that several SNPs of the CYP1A2 and CYP2B11 genes are potential targets for drug sensitivity investigations.
Animals ; Aryl Hydrocarbon Hydroxylases/*genetics/metabolism ; Cytochrome P-450 CYP1A2/*genetics/metabolism ; Dogs/*genetics/metabolism ; P-Glycoprotein/*genetics/metabolism ; *Polymorphism, Single Nucleotide ; Steroid Hydroxylases/*genetics/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

<p>OBJECTIVETo explore the effect of Danhong Injection (DHI) on platelet activation and inflammatory factors in patients of acute coronary syndrome (ACS) after intervention therapy.p><p>METHODSOne hundred ACS patients were randomly assigned to the DHI group and the control group equally. Both were treated with the conventional treatment, including aspirin, clopidogrel, beta-receptor blocker, angiotensin converting enzyme inhibitor, etc. for 2 weeks after percutaneous coronary intervention (PCI), and to the patients in the DHI group, intravenous dripping of DHI was given simultaneously. Fasting venous blood of patients were collected before PCI and on the next morning of PCI to determine the platelet activation indices, expression of CD62p and receptor complex of glucose protein (GP) II b/III a by flow cytometry; plasma fibrinogen C (FIB-C) by scattering turbidimetry, and serum high-sensitivity C-reactive protein (hs-CRP) with emulsoid immuno-enhancing turbidimetric test kit. The outcomes were compared with those determined in 40 healthy persons for control.p><p>RESULTSSerum levels of CD62p, GP II b/III a, FIB-C and hs-CRP in ACS patients were significantly higher than those in the healthy control (all P<0.01), and those were significantly higher after PCI than before PCI (P <0.05 or P<0.01). After being treated for 2 weeks, the 4 platelet activation indices were lowered to different extent in both groups, but the lowering in the DHI group was more significant than that in the control group (P<0.05).p><p>CONCLUSIONDHI can inhibit the platelet activation and inflammatory reaction in ACS patients after PCI.p>
Acute Coronary Syndrome ; metabolism ; therapy ; Aged ; Angioplasty, Balloon, Coronary ; Drugs, Chinese Herbal ; therapeutic use ; Female ; Fibrinogen ; metabolism ; Humans ; Inflammation ; drug therapy ; metabolism ; Male ; Middle Aged ; P-Selectin ; blood ; Platelet Activation ; Platelet Glycoprotein GPIIb-IIIa Complex ; metabolism

The mutation and reduction of mitochondrial DNA (mtDNA) have been suggested as factors in the carcinogenesis. However, whether the depletion of mtDNA induces multidrug resistance in cancer cells has not been fully investigated. To elucidate the association of cellular mtDNA content and drug resistance, we generated HCT-8 colon cancer cells which revealed a marked decrease in cellular mtDNA and ATP content, concomitant with a lack of mRNAs encoded by mtDNA. The mtDNA-depleted cells showed a decreased sensitivity and accumulation of anti-cancer drugs, suggesting that mtDNA depletion could develop multidrug resistance (MDR) phenotype in HCT-8 cells. We found that the expression level of MDR1 mRNA and its translated product P-glycoprotein was increased in the mtDNA- depleted cells, indicating that the decrease of sensitivity and accumulation of anti-cancer drug in the mtDNA-depleted cells might be due to a substantial increase in the expression of P-glycoprotein. Furthermore, increased expression of MDR1 mRNA and P-glycoprotein was due to an increase of mRNA stability rather than transcriptional activation. Taken together, these results indicate that mtDNA depletion can induce an increased P-glycoprotein expression via an increase of mRNA stability and suggest that the mtDNA depletion in cancer cells plays an important role in the induction of MDR phenotype.
Cell Line, Tumor ; DNA, Mitochondrial/*metabolism ; Doxorubicin/pharmacology ; Gene Expression Regulation, Neoplastic/drug effects ; Humans ; P-Glycoprotein/*genetics/metabolism ; Paclitaxel/pharmacology ; Promoter Regions, Genetic/genetics ; *RNA Stability/drug effects ; RNA, Messenger/genetics/metabolism ; Up-Regulation/drug effects/*genetics

BACKGROUND: The multidrug resistance (mdr1), multidrug resistance associated protein (mrp1), and glutathione-s-transferase (gst) pi genes have been associated with treatment failure in acute myeloid leukemia (AML). c-jun N-terminal kinase (JNK) activity is increased in response to chemotherapeutic agent. METHODS: To investigate the significance of multidrug resistance (mdr) parameters and JNK activity, bone marrow or peripheral blood cells from 52 patients with AML were analyzed. RT-PCR was performed for mdr1, mrp1, and gst pi gene expression. JNK expression and activity were measured using an immunoe- nzymatic kinase assay and a western blot method. RESULTS: High level expression of mdr1, mrp1, and gst pi mRNA was observed in 38.5%, 48.1% and 54.3% of AML cases, respectively. The remission rate was significantly low in cases with an older age (>55 yr), a high WBC count, poor chromosomal abnormalities, a high level expression of mdr1 and mrp1. The WBC count and mdr1 mRNA expression were independent predictors for the outcome to induction chemotherapy. There was a shorter duration of overall survival in the patients with an older age, a high WBC count, chromosome aberrations, high level expressions of mdr1 and mrp1 mRNA, and JNK activation. The patient's age, WBC count and chromosomal abnormalities were independent predictors for overall survivals. The majority (28/30) of AML cases did not show any levels of JNK activation except for two cases, which were associated with an extremely high WBC count, chromosomal aberration, high level expressions of mdr1, mrp1 and gst pi mRNA, and treatment resistance. CONCLUSIONS: These data indicate the influences of mdr1 and mrp1 mRNA expression on the clinical outcome of AML to induction chemotherapy. But it will be necessary to investigate further whether blast cells of AML resistant to chemotherapy retain the capacity to activate JNK, and relate to MDR parameters.
Adolescent ; Adult ; Aged ; *Drug Resistance, Multiple/genetics ; *Drug Resistance, Neoplasm/genetics ; Female ; Glutathione S-Transferase pi/genetics ; Humans ; JNK Mitogen-Activated Protein Kinases/*metabolism ; Leukemia, Myeloid, Acute/*drug therapy/genetics/metabolism ; Male ; Middle Aged ; Multidrug Resistance-Associated Proteins/genetics ; P-Glycoprotein/genetics ; RNA, Messenger/*metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Survival Analysis ; Treatment Outcome

It is generally accepted that tissue factor plays an important role in coagulation and intravascular thrombus formation. Tissue factor is not only found primarily on the surface of certain cells that are located outside the vasculature, but also found in circulating cells. Monocyte express tissue factor induced by endotoxin. Recently, many researches indicate that P-selectin, CD40 ligand and GPIIb/IIIa receptor of platelet can also affect expression of tissue factor by monocyters. In addition, a lot of studies showed that tissue factor exist in the circulation including contained platelet. Tissue factor in the platelet releases under certain condition, and initiates coagulation. In this review the relation between platelet and tissue factor was elaborated.
Blood Platelets ; drug effects ; metabolism ; physiology ; CD40 Ligand ; physiology ; Humans ; Monocytes ; drug effects ; metabolism ; P-Selectin ; physiology ; Peptides ; pharmacology ; Platelet Glycoprotein GPIIb-IIIa Complex ; physiology ; Thromboplastin ; biosynthesis ; drug effects ; physiology

<p>OBJECTIVETo detect the redistribution of platelet surface glycoprotein (GP)Ib alpha and cytoskeleton reorganization in the course of thrombin receptor activation, and investigate the mechanism of GPIb alpha re-translocation and the role of thrombin receptors in platelet signal transduction.p><p>METHODSThe thrombin receptor activating peptide (PAR1-AP, TRAP) was used for stimulating platelet at different time points (0 - 60 min), then the platelet surface GPIb alpha and P-selectin were examined with flow cytometry, and the alterations of GPIb alpha, actin and myosin were analyzed in cytoskeleton by Western blot and GPIb alpha immunoprecipitation. Cytochalasin D and/or Apyrase VII were used for investigating their inhibitory effect on platelet activation.p><p>RESULTSAn increase of P-selectin and reversible internalization of GPIb alpha were observed within platelets upon TRAP activation, and transient changes of actin, myosin and GPIb alpha/myosin, GPIb alpha/actin association were also found in this course. These changes were apparently blocked by cytochalasin D, which inhibited the incorporation of GPIb alpha, actin and myosin into cytoskeleton. Apyrase VII had a weak effect on GPIb alpha internalization, although it accelerated the return of GPIb alpha to platelet surface. In addition, Apyrase VII also quickened the GPIb alpha disappearance in cytoskeleton and the dissociation of GPIb/myosin or GPIb/actin during activation.p><p>CONCLUSIONThrombin receptor activation takes part in platelet signal transduction, inducing a reversible redistribution of GPIb alpha. This process is related to cytoskeleton reorganisation and ADP.p>
Actins ; metabolism ; Blood Platelets ; cytology ; drug effects ; metabolism ; Blotting, Western ; Cells, Cultured ; Cytoskeleton ; metabolism ; Humans ; Myosins ; metabolism ; P-Selectin ; metabolism ; Peptide Fragments ; pharmacology ; Platelet Activation ; drug effects ; physiology ; Platelet Glycoprotein GPIb-IX Complex ; metabolism ; Receptors, Thrombin ; metabolism ; physiology

To investigate the changes of platelet activated state and platelet activated function by trace whole blood flow cytometry (FCM), and to explore the mechanism of hemorrhage and infiltration in adults with acute leukemia, the expression percentage and changes of these expressions of CD62p and PAC-1 on platelet surface were determined by FCM of trace whole blood after platelet activated by ADP in patients with new diagnosed AL (group I), complete remission (CR, group II) and continuously complete remission (CCR, group III). Healthy adults were used as control group. The result showed that the expression of CD62p in group I and II was higher than that in control group, before and after platelet activated by ADP (P < 0.01). The expression of PAC-1 in group I was higher than that in control group (P < 0.01), the expression of PAC-1 in group II was lower than that in control group (P > 0.01), There was no significant difference in expression of CD62p and PAC-1 between group III and control group (P > 0.01), and no significant difference was found between AL group with megakaryocyte malignant pathological changes and AL group without megakaryocyte malignant pathological changes before platelet activated by ADP (P > 0.01). After platelet activated by ADP, the expression of PAC-1 in the former was lower than that in the latter (P < 0.01). It is concluded that (1) high level activated platelet in peripheral blood of AL patients show that interaction between activated platelet and leukemia cells can be one of reason resulting in widespread hemorrhage and infiltration AL patiens; (2) the decrease of number and activted function of platelet at the first stage of AL patients may be caused by malignant hyperplasia of leukemia cells and damage of megakaryopoiesis in bone marrow.
Acute Disease ; Adenosine Diphosphate ; pharmacology ; Adolescent ; Adult ; Aged ; Blood Platelets ; cytology ; metabolism ; Cell Membrane ; drug effects ; metabolism ; Female ; Flow Cytometry ; Humans ; Leukemia ; blood ; pathology ; Male ; Middle Aged ; P-Selectin ; biosynthesis ; Platelet Activation ; drug effects ; physiology ; Platelet Glycoprotein GPIIb-IIIa Complex ; biosynthesis

<p>OBJECTIVEBy observing the effect of API 0134, an active ingredient of green chiretta, on platelet membrane glycoprotein (GP) in patients with hyperlipemia to explore the mechanism of the anti-platelet aggregation effect of API.p><p>METHODSThe mean immunofluorescent intensity (MFI) of the platelet membrane glycoprotein GP II b/III a, GPIb, P-selectin (GMP-140) and von Willebrand's factor (vWF) in resting platelet, activated platelet (untreated or treated with API 0134 of different concentrations) were detected in 30 randomly selected patients with hyperlipemia, using immunofluorescent marker and flow cytometry.p><p>RESULTSAPI of all concentrations (25 mg/L, 50 mg/L and 100 mg/L) could significantly decrease the MFI of GP II b/III a in a positive dose-dependent manner, as compared with that in activated platelet untreated with API; API of 50 mg/L and 100 mg/L could also reduce the MFI of GMP-140 and vWF in activated platelet (P < 0.01); but API of 100 mg/L showed insignificant influence on GPIb expression in activated platelet membrane.p><p>CONCLUSIONAPI 0134 exerts obvious anti-platelet GP II b/III a effect on activated platelets, middle or large dose of API also shows inhibiting effect on GMP-140 and vWF expression in platelet.p>
Aged ; Andrographis ; chemistry ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Female ; Humans ; Hyperlipidemias ; blood ; drug therapy ; Male ; Middle Aged ; P-Selectin ; blood ; Phytotherapy ; Platelet Glycoprotein GPIIb-IIIa Complex ; metabolism ; von Willebrand Factor ; metabolism