Preliminary Investigation Of Change About Platelet-associated Angiogenesis Factor During The Early Stage Of Diabetes In Vitro And In Vivo

Part I Preliminary study of parameter changes and expression of MMPs and TIMPs in platelet from patients with type 2 diabetes mellitusObjective To investigate the change of platelet parameters and the expression of MMPs and TIMPs in platelet in patients with type 2 diabetes. Methods Platelet counts, MPV and PDW were measured in 54 patients with type 2 diabetes and 46 healthy people. Real-time PCR was performed to compare the expression of MMPs and TIMPs in both groups. Results MPV and PDW in patients were higher than those in controls(P<0.05). The expression levels of platelet-derived MMPs and TIMPs in patients were higher than those in controls(P<0.001). Conclusion MPV, PDW can serve as parameters of platelet dysfunction in newly diagnosed diabetes. Platelet-derived MMPs and TIMPs may be important in evaluating the role of platelet in vascular complication of diabetes.Part II Investigation of changes of platelet-associated angiogenesis factors during the early stage of diabetesObjective: To investigate the function of platelet in early diabetic stage as reflected by the changes of the platelet associated angiogenesis factors and the expression of corresponding genes in target organs related to diabetic complications. Methods: In in vitro study, the platelets were cultured with glucose, AGEs or Ox LDL at 37℃ for 60 min and 120 min, and platelet aggregation rate, expression of MMPs,TIMPs, VEGF, PDGF and endostatin were measured in platelets. In in vivo studies, intraperitoneal STZ was used to induce diabetes in mice. Platelet count and aggregation stimulated ADP or thrombin were measured, and angiogenesic-associcated genes were detected in platelets, kidneys, vessels and eyes at 4, 6, 8 and 10 weeks after STZ injection. Also, platelets were separated from diabetic model and control mice, and their RNA was subjected to.microarray assay for idenfying differential expressed genes between STZ-treated mice and control. Results: Activity of platelets was increased after incubating with AGEs, Ox LDL and glucose. Real-time PCR showed that AGEs and Ox LDL can increase both proangiogenic factors and antiangiogenic factors in vitro. The aggregation rate of platelets in STZ-treated mice was slightly increased compared with controls; meanwhile, proangiogenic genes and their inhibitors in platelet manifested differential expression. Microarray profiling in platelet during the early stage of diabetes identified changes of genes with diverse biological processes and molecular functions, such as cell cycle and B cell signal pathway. The pathway of NF-kappa B and JAK-STAT were both downregulated as revealed KEEG analysis. Conclusion: Functional change and the differential expression of platelet-derived proangiogenic and antiangiogenic factors in both platelet and target organs prone to diabetic complication were observed among diabetes early stage, demonstrating a possibility of using anti-platelet protocols for treatment or prevention of the vascular complications of diabetes.