Protective Effects Of Fenofibrate On Endothelial Progenitor Cells From Human Peripheral Blood Induced By CRP And The Possible Mechanisms

Chart 1 Changes of circulating endothelial progenitor cells (EPCs)and inflammatory factors in patients with coronary artery disease before and after percutaneous coronary interventionObjecive:To investigate endothelial progenitor cells from peripheral blood and detect inflammatory factors in patients with coronary heart diseases before and after percutaneous coronary intervention(PCI).Methods:94 cases were divided into 2 groups:CAD group(n=64) and control group(n=30),Mononuclear cells isolated from peripheral blood of patients with coronary artery diseases before,after PCI and after 4 days by Ficoll-density centrifugation.The isolated cells were cultured in 1640 medium supplemented with VEGF and bFGF.The EPCs specific surface mark CD34 and KDR were assessed by fluorescence activated cell sorter(FACS)analysis.EPCs were characterized as adherent cells double positive for DiL-acLDL uptake and FITC-UEA-I binding by direct fluorescent staining under a fluorescence microscope.EPCs proliferation and migratory were assayed by MTT assay and Chemotaxis assays.The concentrations of serum CRP and TNF-αwere measured by immunoturbidimetric test and enzyme linked immunosorbent assay (ELISA)before and after PCI and after 4 days.Results:The number of EPCs was reduced in patients with CAD before PCI,but number was significantly increased in patients with CAD after PCI compared with in patients with CAD,and the number was reduced in patients with CAD after PCI 4 days.In addition,the proliferation of EPCs have not this change as the number at patients before and after PCI.The concentrations of serum CRP and TNF-αafter PCI were higher than those of before PCI.Conclusion:1,The levels of circulating EPCs of CAD patients were lower than those of healthy person.2,PCI would lead to increasing of endothelial progenitors cells at patients after PCI,but after PCI 4 days,this increasing would not exist.3,The levels of serum CRP and TNF-αof CAD patients were higher than those of healthy person.Levels of serum CRP and TNF-αincreased after PCI.Charter 2 Influence of C-reactive protein on endothelial progenitor cells from health human peripheral blood and the possible mechanismsPart 1 Influence of C-reactive protein on the number and the function of endothelial progenitor cells and the antagonism of FenofibrateObjective:To investigate the effects of c-reactive protein(CRP)on the proliferation of endothelial progenitor cells(EPCs)of peripheral blood and observe whether fenofibrate can antagonize the effects of CRP.Methods:.Mononuclear cells were isolated from peripheral blood and cultured for 7days,Attached cells were characterized with both DiL-acLDL uptake and FITC-UEA-I binding.EPCs were incubated with different concentration of CRP(1μg/ml,2.5μg/ml,5μg/ml)among different times(24,48,72hr)and different concentration of fenofibrate (5μmol/L,10μmol/L,50μmol/L)MTT assay was used and colony forming units(CFU)were quantified to evaluate the proliferation of EPCs after treated with CRP and fenofibrate.Meanwhile,Chemotaxis assays were used to quntified EPCs induced by VEGF.Nitric oxide(NO)in the supernatant was measured by nitrate reductase assay.Results:1,Incubation of EPCs withCRP dose and time-dependently decreased the number and the function of EPCs.2,In addition,the depressant effect of CRP on EPCs were dismissed after giving the inceasing dosage of fenofibrate.3,CRP significantly inhibited the production of NO.Fenofibrate increased NO generation.ConclusionsIt is suggested that CRP can promote endothelial dysfunction by means of depressant EPCs proliferation and migratory,however, fenofibrate can play antagonism on CRP-induced EPCs.Part 2 Protective effects of Fenofibrate on function of endothelial progenitor cells from peripheral blood impaired by CRP and the possible mechanismsObjective:Recent studies have demonstrated that reduced EPCs numbers and activity was associated with EPCs senescence which involved telomerase activity.Therefore,we investigated whether CRP accelerated the onset of EPCs senescence and whether fenofibrate can antagonize the effects of CRP.Furthermore,this study aims to explore the possible mechanisms responsible for CRP on EPCs.Methods:EPCs were isolated from peripheral blood and characterized.After exvivo cultivation,EPCs became senescent as determined by acidicβ-galactosidase staining.To get further insights into the underlying mechanisms of these effects induced by CRP and fenofibrate,we measured human telomerase reverse transcriptase(hTERT) and eNOS mRNA expression and determined the eNOS by using western blot.Results:1,CRP dose-dependently accelerated the onset of EPCs senescence in culture.Moreover,fenofibrate can inhibited CRP-induced senescence.2,CRP dose-dependently inhibited hTERT and eNOS mRNA expression.However,fenofibrate can up-regulation the expression of hTERT mRNA in EPCs and up-regulation the expression of both eNOS mRNA and protein in EPCsConclusions:1,CRP accelerated the onset of EPCs senescence,leading to cellular dysfunction.The effect of CRP might be dependent on telomerase inactivation,and eNOS also appeared to play a major role.2,Fenofibrate preventative effect against CRP-induced EPCs senescence.