The Research On Platelet Activity, The Underlying Mechanism And Security Modulated By New Type Of STAT3 Inhibitor KIF

Purpose: By observing the new STAT3 inhibitors KIF influence on platelet aggregation, activation, release, blood clots, toxicity and coagulation function, as well as to the protein expression of phosphorylation STAT3, AKT, P65 and Src in platelets, to explore its anti-platelet activity,possible mechanism and security.Methods: Washing platelet from healthy adults whole blood as the research object, Experimental group used KIF incubation, the control group treated with isodose DMSO, and then two groups respectively with collagen and thrombin revulsant processing. Turbidimetric method detected platelet aggregation curve between experimental group and control group. Flow cytometry instrument detected platelet surface integrinαⅡbβ3 and P-selectin(CD62P) expression of two groups. Image software compared the average size of the circular platelet clumps onto a glass slide in fibrinogen package of two groups. Imaging record time of platelet thrombus solidification conditions in 10 minutes, 15 minutes, 20 minutes, 30 minutes between two groups. Western blot method detected the expression of phosphorylation signal protein STAT3, AKT, P65 and Src within the platelet. Alamar Blue and Annexin V method respectively detected effects on toxic and apoptosis of platelets treating KIF. Animal experiment is made in suzhou university’s center for animal C57B6 is 6-8 weeks of mice 30, randomly divided into two groups, experimental group used KIF intraperitoneal injection, the control group with isodose DMSO, 45 minutes post-processing mice tail vein, compared mice tail vein bleeding time of two groups, to observe the effects of KIF on blood coagulation function.Results :(1) The influence of KIF 1.25, 2.5, 5μM for platelet maximum aggregation rate: the influence of collagen group(2 ug/ml) make the platelet aggregation rate fell about 14%, 33% and 61%, respectively, thrombin group(0.02 u/ml) fell about 16%, 32% and 68% respectively.(2) KIF 5μM inhibited P- selectin(CD62P) expression 85.4% of platelet surface induced by thrombin(0.1 u/ml),(P(27)0.05).(3) KIF 5μM inhibited integrinαⅡbβ3 activation 77.2% of platelet surface induced by thrombin(0.1 u/ml),(P(27)0.05).(4) KIF 1.25μM can inhibit platelet activation in 32.2%-67.8% and 5μM can inhibit 50.8%-85.6% of platelet activation(P < 0.05).(5) KIF 5μM can significantly inhibit platelet thrombus retraction in 10 to 20 minutes(P < 0.05).(6) KIF(1.25, 2.5, 5μM) inhibited the expression of phosphorylation signal protein STAT3(P < 0.05), but P- Akt, P- P65, P- Src were no obvious inhibition(P >0.05).(7) Platelet survival rates were 96.8%, 95.4% treated by KIF 5,10μM. Compared with the control group, P > 0.05, there was no statistically significant difference.(8) The percentage of the apoptosis cells gate number are 0.62% and 1.04% respectively treated by KIF 5,10μM. Compared with the control group, P > 0.05, there was no statistically significant difference.(9) The bleeding time of the mouse tail vein treated by KIF 2 mg/kg was 258.7±72.3 seconds(N = 11), the control group was 214.2±66.65 seconds(N = 10), the experimental group and control group had no significant difference(P > 0.05).Conclusions: KIF can inhibit the platelet aggregation, release, activation and thrombus clot retraction links induced by thrombin and collagen, may be through the JAK2 / STAT3 signaling pathway. KIF does not affect Platelet activity and apoptosis,and do not affect blood coagulation function.