ABSTRACT
The purpose of this study was to determine the combined effect of transmyocardial laser revascularization (TMLR) and the implantation of endothelial progenitor cells (EPCs) on cardiac function of ischemic hearts in canines. The left anterior descending artery (LAD) was occluded to establish the canine model of acute myocardial infarct (AMI). Four weeks later, the animals were randomly divided into four groups: TMLR group, in which transmyocardial laser-induced channels were established at the ischemic region; EPCs+TMLR group, in which EPCs were locally transplanted into laser-induced channels at the ischemic region; EPCs group, in which the EPCs were injected into the ischemic region; control group, in which the AMI animals received neither TMLR nor EPCs. The peripheral blood (50 mL) was sampled in all groups. Mononuclear cells from the peripheral blood were separated and cultured to obtain spindle-shaped attaching (AT) cells in vitro. AT cells were labeled with 1, 1'-dioctadecyl-1 to 3,3, 3',3'-tetramethyl-indocarbocyanine perchlorate (DiI) before injecting into the laser-induced channels or ischemic region. Four weeks after the first operation, TMLR was performed in the TMLR group and EPCs+TMLR group, and at the same time, the EPCs originating from the AT cells were mixed with calcium alginate (CA). Then the EPCs-CA composites were implanted into myocardial channels induced by laser in the EPCs+TMLR group, and into the myocardial infarct area in the EPCs group. All dogs underwent echocardiography at second month after LAD occlusion. Finally the samples of myocardium around the LAD were subjected to histochemical and immunohistologic examinations. The results showed there was no significant difference in the diameter of left atrium and ventricle before treatment among all groups (P>0.05). Eight weeks after modeling, the regional contractility in the LAD territory in the EPCs+TMLR group was increased as compared with control group and TMLR group, but there was no significant difference between control group and TMLR group. Neoangiogenesis was observed in the EPCs+TMLR group, and the fibrosis was seen in the TMLR group. There was no significant difference in neoangiogenesis around the channels induced by laser among EPCs+TMLR, EPCs and TMLR groups. It was concluded that TMLR combined with EPCs could improve the regional and global cardiac function in AMI, and augment neovascularizaiton in channels of ischemic myocardium induced by laser.
ABSTRACT
The purpose of this study was to determine the combined effect of transmyocardial laser revascularization (TMLR) and the implantation of endothelial progenitor cells (EPCs) on cardiac function of ischemic hearts in canines. The left anterior descending artery (LAD) was occluded to establish the canine model of acute myocardial infarct (AMI). Four weeks later, the animals were randomly divided into four groups: TMLR group, in which transmyocardial laser-induced channels were established at the ischemic region; EPCs+TMLR group, in which EPCs were locally transplanted into laser-induced channels at the ischemic region; EPCs group, in which the EPCs were injected into the ischemic region; control group, in which the AMI animals received neither TMLR nor EPCs. The peripheral blood (50 mL) was sampled in all groups. Mononuclear cells from the peripheral blood were separated and cultured to obtain spindle-shaped attaching (AT) cells in vitro. AT cells were labeled with 1, 1'-dioctadecyl-1 to 3,3, 3',3'-tetramethyl-indocarbocyanine perchlorate (DiI) before injecting into the laser-induced channels or ischemic region. Four weeks after the first operation, TMLR was performed in the TMLR group and EPCs+TMLR group, and at the same time, the EPCs originating from the AT cells were mixed with calcium alginate (CA). Then the EPCs-CA composites were implanted into myocardial channels induced by laser in the EPCs+TMLR group, and into the myocardial infarct area in the EPCs group. All dogs underwent echocardiography at second month after LAD occlusion. Finally the samples of myocardium around the LAD were subjected to histochemical and immunohistologic examinations. The results showed there was no significant difference in the diameter of left atrium and ventricle before treatment among all groups (P>0.05). Eight weeks after modeling, the regional contractility in the LAD territory in the EPCs+TMLR group was increased as compared with control group and TMLR group, but there was no significant difference between control group and TMLR group. Neoangiogenesis was observed in the EPCs+TMLR group, and the fibrosis was seen in the TMLR group. There was no significant difference in neoangiogenesis around the channels induced by laser among EPCs+TMLR, EPCs and TMLR groups. It was concluded that TMLR combined with EPCs could improve the regional and global cardiac function in AMI, and augment neovascularizaiton in channels of ischemic myocardium induced by laser.
Subject(s)
Animals , Dogs , Humans , Coronary Circulation , Coronary Vessels , Pathology , General Surgery , Muscle Contraction , Physiology , Myocardial Ischemia , Pathology , Therapeutics , Myocardium , Pathology , Neovascularization, Physiologic , Physiology , Stem Cell Transplantation , Methods , Stem Cells , Transmyocardial Laser Revascularization , MethodsABSTRACT
<p><b>OBJECTIVE</b>To observe the effects of NBD-peptide pretreatment of the donor dendritic cells in immune tolerance induction in mouse allograft recipients and investigate the mechanisms.</p><p><b>METHODS</b>BALB/c mouse DCs pretreated with NBD-peptide (NBD-Peptide-DC) were injected into the recipient C57BL/6 mice 7 days before transplantation. Cervical heterotopic heart transplantation model was established using the cuff technique and the cardiac allograft survival time was observed. Pathological analysis were performed to examine the graft injection and the responsiveness of the recipient spleen T cell to the donor alloantigen was determined by mixed lymphocyte reaction (MLR). The serum levels of cytokines were determined using ELISA.</p><p><b>RESULTS</b>The cardiac allograft survival time in the NBD-Peptide-DC-treated group (21.83-/+3.54 days) was significantly longer than that in the Day9-DC group (13.33-/+2.58 days) and PBS-treated group (6.66-/+1.21 days) (P<0.01), with also significantly lower pathological grade for graft rejection (P<0.01). The donor-derived NBD-Peptide-DCs induced alloantigen-specific T-cell hyporesponsiveness. In the NBD-Peptide-DC-treated group, the serum levels of IL-12 and IFN-gamma decreased significantly (P<0.01), but the levels of IL-4 and IL-10 increased significantly (P<0.01).</p><p><b>CONCLUSION</b>Injection of donor-derived NBD-Peptide-DCs can leads to donor-specific tolerance in the transplant recipients, and the induction of recipient T-cell hyporesponsiveness and polarization of Th2 response may play important roles in immune tolerance to cardiac allografts.</p>