| Objective：To observe whether bone-derived mesenchymal stem cells (BMSCs) infectedwith lentiviral vectors bearing miR-1have therapeutic effect on myocardia infarction(MI) in rat, and to investigate the relevant mechanism, and thus to find the potentialnew strategy to treat MI.Methods：BMSCs were isolated through density gradient centrifugation combined withadherence, and amplified and identified. The lentiviral vectors bearing GFP-miR-1were constructed. The AMI rat model were established through left anteriordescending. The rats (n=30) were randomly divided into the following groups: blankcontrol, Sham group, myocardia infarction group(Vehic), AMI transplanted withBMSCs without miR-1(BMSCs), and MI transplanted with BMSCs carrying mir-1(mir/BMSCs). N=6in each group. One day after AMI was established, the rats ineach group were injected with100ul physiological saline solution or2X106BMSCscells, respectively. The rats in each groups were feeded for28days. The cardiacfunctions and structural changes were observed through echocardiography before and28days after animal model establishment. After feeding for28days, the rats in eachgroup were sacraficed, and the serum VEGF level in the serum was measured byELISA.The heart were isolated to caculate the heart quality index. The myocardialpathological change was detected by HE staining. The expression of vascular VIIIfactor and myocardial specific protein cTNT and connexin43were detected by IHCand immunohistochemistry, respectively.Results：BMSCs started attached to the bottom after48hours of density gradientcentrifugation. The shape of the attached cells were short rods or flat polygonal-like.The cells grew slowly at the first3days, and some small clony was observed, andthen the cells grew fast. Flow cytometry analysis showed that the cells showed theBMSC phenotype: CD29-, CD44-positive and CD34-,CD45-negative.The lentiviral vectors overexpressing miR-1were constructed successfully (the virus titer was3X108TU/ul). BMSCs were infected with lentivirus bearing mir-1. The transfectionefficiency was above90%on day4after transfection and the strong miR-1expression was detected. The echocardiography results in each group has nosignificant difference before rat model establishment.28days after the rat model wasestablished, we observed that the echocardiography index was improved in BMSCsand mir-1/BMSCs groups, especially in the latter group. The result of ELISA assayshowed that the VEGF concentration was increased in BMSCs and mir/BMSCs group.The increase of VEGF concentration in mir/BMSCs group was the most obvious. TheHE staining showed that the necrosis and scarring formation mir/BMSCs group weresignificantly less than other groups. The expression of vascular VIII factor by IHCassay indicated that the capillary density in mir/BMSCs group was more than othergroups. The immunohistochemistry analysis showed that the BMSCs in themyocardia infarction area in the rats of miR-1/BMSCs group had the expression ofmyocardial cell-specific protein cTNT and connexin43.Conclusions：Transplantation of BMSCs carrying miR-1could improve cardiac remodelingafter myocardia infarction in SD rat, and partially inhibit or reverse ventricularremodeling. miR-1-modified BMSCs could further improve the therapeuticeffeciency of myocardia infarction. It is possible that the miR-1-modified BMSCspromote the differentiation of cardiac stem cells to myocardia cells and improve thesecretion of VEGF through paracrine mechanism, and thus realize the therapeuticapplication in myocardia infarction. |
PDF Full Text Request