| Objective To investigate the oxidative preconditioning impact on mesenchymal stem cells anti-apoptosis in vitro and migration in vivo, the oxidative preconditioning or untreated bone marrow mesenchymal stem cells (MSCs) were transplanted into swine through Digital Subtraction Angiography after sucessfully creating the model of myocardial infarction in swine by embolization of the left coronary artery with a gelation sponge through cardiac catheter. The change of heart function was detected. Both were compared and the mechanism was preliminarily approached.Methods Put three generations of MSCs into twelve orifice plate petri dish to be cultivated. MSCs were exposed to different doses of H2O2 for 24 h, respectively. Flow cytometry analysis for MSCs apoptosis induced by different doses of H2O2. CXCR4 protein expression was detected by flow cytometry. Bcl-2 protein expression was detected by western blot. Twenty swines were randomly divided into four groups. Group A was a control group; Group B received a stem cell transplantation without oxidative preconditioning in acute period after MI; Group C received a stem cell transplantation with oxidative preconditioning at the same period; Group D received untreated stem cells transplantation 4 weeks after MI; Myocardial infarction Model is established by gelatin sponge embolization. Four weeks later, hemodynamics were used to assess the heart function. The autologous bone marrow stem cells (1×107 / 5 mL) were injected transcatheterly into the remote embolization of LAD. The change of each index of cadiac function was detected by Powerlab8SP + Millar catheter and ECT. The migration and field planting of MSCs with Ferumoxides markers were detected by MRI. Hearts histological detection was done 4 weeks after stem cell transplantation.Vessel number was also counted by immuno-histochemisty staining with anti Factor-Ⅷantibody.Myocardial cells were detected by TUNEL .Results Low concentration of H2O2 did not increase cell apoptosis(p >0.05). Comparing with untreated cells, 20μM H2O2 treatment of MSCs for 24 h induced a marked increase in membrane expression of CXCR4(p<0.05). The membrane expression of Bcl-2 was also increasing(p<0.05). Compared group C with group B(1) Left ventricular function, including LVDP,+dp/dtmax,-dp/dtmax was significantly improved(p<0.05). (2)Left ventricular infarction area significantly decreased (p<0.05).(3)A prussian blue stain displayed MSCs migration and field planting around myocardial infarction increased obviously through hearts histological (p<0.05).(4)New vessels density in infarction junctional zone increased obviously after transplantation(p<0.05). (5)The detection of TUNEL displayed apoptosis of myocardial cells significantly reduced(p<0.05). Compared group C with group D: (1)Left ventricular function, including LVDP,+dp/dtmax,-dp/dtmax was significantly reduced (p<0.05).(2)The reduction of left ventricular infarction area decreased (p<0.05)(.3)New vessels density in infarction junctional zone reduced after transplantation(p<0.05).Conclusions 1,Low concentration of H2O2 did not increase cell apoptosis. It could improve the membrane expression of CXCR4 and Bcl-2. 2,Oxidative preconditioning could promote MSCs migration and field planting around myocardial infarction. 3,After pretreatment of stem cells transplantation could improve the blood supply in the infarction junctional zone. 4,After pretreatment of stem cells transplantation could increase heart function.
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