ABSTRACT
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.
Subject(s)
Humans , Blood Platelets , Cell Biology , Metabolism , Cell Separation , Cyclosporine , Pharmacology , Dual Specificity Phosphatase 2 , Genetics , Metabolism , Gene Expression Regulation , Interleukin-17 , Metabolism , Pharmacology , Membrane Potential, Mitochondrial , Mitochondria , Metabolism , Mitochondrial Membrane Transport Proteins , Genetics , Metabolism , Mitogen-Activated Protein Kinase 1 , Genetics , Metabolism , P-Selectin , Genetics , Metabolism , Phosphorylation , Platelet Activation , Platelet Aggregation , Primary Cell Culture , Signal Transduction , Tumor Suppressor Protein p53 , Genetics , MetabolismABSTRACT
This study was purposed to explore the expressions of platelet-activated markers PAC-1 and CD62p in peripheral blood of malignant lymphoma patients and the influence of dipyridamole on their expression. 32 lymphoma patients were divided into simple chemotherapy group (simple group) and chemotherapy plus dipyridamole group (combined group) randomly, and 15 healthy peoples were selected as control group. The dipyridamole of 100 mg/day was given to the patients in combined group. The expression levels of PAC-1, CD62p and fibrinogen (Fib) were detected by flow cytometry and magnetic bead method on day 0, 3, 7 and 14 of chemotherapy respectively. The results showed that the levels of PAC-1, CD62p and Fib in lymphoma patients were significantly higher than those in control group (p < 0.01, 0.05), moreover there was positive correlation between levels of PAC-1 and Fib (r = 0.549, p < 0.01). PAC-1 expression on day 0 and 3 of chemotherapy in simple group was higher than that on day 14 (p < 0.05, 0.01) and CD62p expression on day 3 of chemotherapy was higher than that on day 0, 7 and 14 (p < 0.05, 0.01). PAC-1 expression in combined group on day 14 of chemotherapy was lower than than on day 0 and 3 (p < 0.05, 0.01), and CD62p on day 14 was lower than that on day 3 of chemotherapy (p < 0.05); PAC-1 and CD62p expressions in combined group on day 3, 7 and 14 of chemotherapy were decreased than those in simple group, but Fib level was not changed significantly. It is concluded that the patients with malignant lymphoma usually accompany with platelet activation and hyperfibrinogenemia in peripheral blood. Applying dipyridamole routine dosage in chemotherapy can efficiently restrain platelet activation.
Subject(s)
Adolescent , Adult , Aged , Female , Humans , Male , Middle Aged , Young Adult , Dipyridamole , Therapeutic Uses , Dual Specificity Phosphatase 2 , Metabolism , Fibrinogen , Metabolism , Lymphoma , Blood , Drug Therapy , P-Selectin , Metabolism , Platelet ActivationABSTRACT
<p><b>OBJECTIVE</b>To investigate the role of cytoplasmic domain of integrin alpha IIb in platelet signal transduction.</p><p><b>METHODS</b>Binding capacity of integrin alpha IIb(R995A) to antibody platelet activation complex-1 (PAC-1) and pp125 focal adhesion kinase (FAK) phosphorylation of cells were detected by flow cytometry, immune precipitation, and Western blotting.</p><p><b>RESULTS</b>Without activation, wild-type alpha IIb beta3 Chinese hamster ovary (CHO) cells failed to bind to PAC-1, but mutant chimera alpha IIb(R995A)beta3 CHO cells were able to bind with PAC-1. Furthermore, phosphorylation of pp125 (FAK) in wild-type alpha IIb beta3 CHO cells occured only when cells were adhered to fibrinogen, but could not be detected in bovine serum albumin suspension. However in the mutant chimera group, it could be detected in both conditions.</p><p><b>CONCLUSION</b>The mutation in integrin alpha IIb(R995A) alters its affinity state as a receptor, thus also mediating cytoplasmic signal transduction leading to the phosphorylation of pp125 (FAK) without ligand binding.</p>
Subject(s)
Animals , Cricetinae , Humans , Blood Platelets , Metabolism , CHO Cells , Cell Adhesion , Cricetulus , Cytoplasm , Metabolism , Dual Specificity Phosphatase 2 , Focal Adhesion Kinase 1 , Focal Adhesion Protein-Tyrosine Kinases , Phosphorylation , Platelet Glycoprotein GPIIb-IIIa Complex , Genetics , Metabolism , Physiology , Point Mutation , Protein Phosphatase 2 , Protein Tyrosine Phosphatases , Metabolism , Protein-Tyrosine Kinases , Metabolism , Signal Transduction , TransfectionABSTRACT
<p><b>OBJECTIVES</b>To explore the relationships between the peripheral blood levels of CD61, CD63, PAC-1 and the incidence of acute rejection and tubular necrosis after renal transplantation, and recovery of the graft function.</p><p><b>METHODS</b>The peripheral blood levels of CD61, CD63, and PAC-1 of 86 patients with uremia in different stages before and after transplantations were analyzed by flow cytometry. The patients were divided into three groups: (1) twenty-nine patients with normal grafts function, (2) hirty with acute rejection and (3) twenty-seven with acute tubular necrosis. The patients with acute rejection were randomly divided into treatment group with anticoagulants and cntrol group.</p><p><b>RESULTS</b>The peripheral blood levels of CD61, CD63 and PAC-1 significantly increased (P < 0.05) in the patients with acute rejection, in comparison with those with normal grafts function and those with acute tubular necrosis. The peripheral blood levels of CD61, CD63 and PAC-1 in patients with acute rejection in anticoagulants therapy was lower, recovery time of the grafts function was shorter, one-year survival rates of patients and grafts were higher, as compared with those of controls.</p><p><b>CONCLUSIONS</b>The patients with acute rejection have significantly high peripheral blood levels of CD61, CD63 and PAC-1 before transplantation, however, these values in patients with acute tubular necrosis are not high, this suggesting that acute rejection might relate to platelet activation, while acute tubular necrosis might not relate to it. After anticoagulants therapy in patients with acute rejection, the grafts function might recover faster and their one-year survival rates and grafts might be higher in those with CD61, CD63 and PAC-1 decreasing remarkably.</p>