| Background and ObjectivesAcute myocardial infarction(AMI) which is fatalness,is one of cardiovascular diseases.Clinical therapies involve thrombolytic therapy,percutaneous intracoronary arterial stenting,coronary artery bypass grafting and heart transplantation etc.These treatments can restraint extent of cardiac myocyte apoptosis,but cann't invert necrotic cardiocytes and improve cardiac insufficiency which results from myocardial infarction.In recent decades,with the study of stem cell which has multiple differentiative potents,we can employ marrow stem cell transplantation to treat myocardial infarction.Bone mesenchymal stem cells (BMSCs) have some merits,such as easy to get and separate,with weak immuongenicity and so on. Some experiments have confirmed that marrow stem cell transplantation which used to treat myocardial infarction,can not only accelerate the vessels,but also lessen cardiac myocyte apoptosis.But the mechanism needs further study.The present experiment was aimed at exploring the influence of marrow stem cell transplantation on the expression of Bcl-2 and PDCD5 in rats with acute myocardial infarction.Methods1.Grouping:45 healthy SD male rats were divided into three groups randomly:control group,AMI group and cell transplantation group(BMSCs group),and each group contain 15 rats.The anterior descending coronary artery was ligated to set up a animal model of AMI in AMI group and BMSCs group,while thoracotomy was performed in control group,but the anterior descending coronary artery wasn't ligated.2.BMSCs culture and labeling in vitro:With thighbone marrow of suckling mouse for the source,MSCs were isolated and purified with adherence plasticity method. MSCs were labeled by 5-bronmodeoxyuridine(BrdU) and were standby.3.Transplantation methord:BMSCs transplantation was carried out 30min after coronary ligation. BMSCs which were labeled BrdU (about 200μL) were injected into four different sites in visceral pericardium of schemia surrounding.AMI group and control group were injected with equal dosage of normal saline.4.Experiment detection:These rats were sacrificed four weeks after BMSCs transplantation.Cardiocyte apoptosis index was determined by terminal deoxynucleotidyl transfease-mediated dUTP nick-endlabeling(TUNEL)methods. Positive cells which were labeled by the BrdU,level of Bcl-2 and PDCD5 were detected by immunohistochemical technique.Polymerase Chain Reaction was emploied to measure expression of mRNA of PDCD5.ResultsFour weeks after transplantation,focal bone mesenchymal stem cells which were positive for BrdU were observed in cardiac myocyte where coagulative necrosis occurring in the BMSCs group.Compared with AMI group,cardiocyte apoptotic index and the expression of PDCD5(mRNA and protion) were significantly lower in BMSCs group(P<0.05). The expression of Bcl-2 in non-infarcted zone was significantly lower in AMI group than that in BMSCs group (P＜0.05).ConclusionsBone mesenchymal stem cells transplantation can lessen cardiac myocyte apoptosis in rats with acute myocardial infarction.Conceivable mechanism may be associated with the high level expression of Bcl-2 (protein) and low level expression of PDCD5 (protein and mRNA) rusulting form BMSCs transplantation. |
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