The Research On Expression And Signal Pathway Mechanism Of Statins Inhibiting Plasminogen Activator-1Induced By High Glucose In Microvascular

Vascular diseases are the most serious complications of diabetes, most diabeticpatients died of cardiovascular and cerebrolvascular atherosclerosis and diabeticnephropathy. The risk of cardiovascular events is significantly higher in diabetic patientswith microvascular complications. Therefore, it’s extremely important to call for morefocus and studies on microvascular complications of type2diabetes to prevent majorvascular events and induce mortality. The abnormity of fibrinolytic system plays animportant role in diabetic complications. The most important fibrinolytic inhibitor isplasminogen activator (PAI-1) which is linked to the onset and development ofcardiovascular and cerebrolvascular diseases.Statins has multifunctional benifits except lipid lowing such as fibrinolysis, improvingendothelial function and antithrombin effect, etc. Whether diabetic patients withmicrovascular complications could benefit more from statins treatment by improvingfibrinolysis and the mechanism of fibrinolytic effects of statins deserves further studies.That’s the main content of this study. Objective The aim of our study was to compare the effect of simvastatin on reducingplasma plasminogen activator inhibitor-1levels in diabetic patients with or withoutmicrovascular complications.Methods We enrolled129type2diabetic patients with (n=79) and without (n=50) diabetic microvascular complications and56control subjects. Plasma PAI-1levels weremeasured by ELISA before and after3months simvastatin treatment in18diabetic patientswith and17without microvascular complications. Common lipid and glucose metabolicparameters were also measured.Results Diabetic patients have higher PAI-1lever compared with matched healthysubjects, and those with microvascular complications exhibited significantly higher levelsof PAI-1than those without. Plasma PAI-1levels were significantly reduced after3monthstreatment of simvastatin. The degree of reduction of PAI-1in group of microvascularcomplications was greater than that of group of diabetes without microvascularcomplications.Conclusion Type2diabetes exhibited impaired fibrinolytic function, and more severeimpairment observed in group with microvascular complications. Therapy with simvastatinimproved fibrinolytic function，thus diabetic patients with microvascular complicationsbenefit more compared with those without microvascular complications. Objective This study was to compare two methods of isolating adult rat cardiacmicrovascular endothelial cells (CMEC) and improve the methods.Methods We use tissue adhere method and enzyme digestion procedure respectivelyto isolate CMEC. Immunofluorescence assay was used to identify specific expression ofCD31on the surface of CMEC.Results We isolated CMEC successfully by these two different methods. The positiverates of CD31were no less than95%. The method of enzyme digestion not only has theadvantage of shorter time to gain a certain amount of cells, it is also a stable procedure toget relatively higher purity of cells compared to tissue adhere method.Conclusion We recommend using the method of enzyme digestion to obtain highpurity CMEC in good condition. Objective The aim of this study was to investigate the possible proinflammatorysignaling pathways involved in statin inhibition of glucose-induced plasminogen activatorinhibitor-1(PAI-1) expression in cardiac microvascular endothelial cells (CMECs).Methods Primary rat CMECs were grown in the presence of5.7mmol/L or23mmol/L glucose. PAI-1mRNA and protein expression levels were measured by real-timePCR and ELISA, respectively. A pull-down assay was performed to determine RhoAactivity. IκBα protein expression was measured by western blotting, and NF-κBtranscription activity was determined by a dual luciferase reporter gene assay.Results PAI-1mRNA and protein expression levels were both increased with highglucose concentrations, but they were significantly suppressed by simvastatin andatorvastatin treatment (P<0.01) and the effects were reversed by mevalonate (MVA,100μM) and geranylgeranyl pyrophosphate (GGPP,10μM) but not farnesyl pyrophosphate(FPP,10μM). Such effects were similar to those of a RhoA inhibitor, C3exoenzyme (5μg/mL), inhibitors of RhoA kinase (ROCK), Y-27632(10μmol/L) and hydroxyfasudil (10μmol/L), and a NF-κB inhibitor, BAY11-7082(5μmol/L). High glucose-induced RhoAand NF-κB activations in CMECs were both significantly inhibited by statins (P<0.01).Simvastatin and atorvastatin equally suppress high glucose-induced PAI-1expression.Conclusion These effects of statins may occur partly by regulating theRhoA/ROCK-NF-κB pathway. The multifunctional roles of statins may be particularlybeneficial for patients with metabolic syndrome.