RESUMO
Bone marrow mesenchymal stem cells (MSCs) are considered as a promising cell source to treat the acute myocardial infarction. However, over 90% of the stem cells usually die in the first three days of transplantation. Survival potential, migration ability and paracrine capacity have been considered as the most important three factors for cell transplantation in the ischemic cardiac treatment. We hypothesized that stromal-derived factor-1 (SDF-1)/CXCR4 axis plays a critical role in the regulation of these processes. In this study, apoptosis was induced by exposure of MSCs to H(2)O(2) for 2 h. After re-oxygenation, the SDF-1 pretreated MSCs demonstrated a significant increase in survival and proliferation. SDF-1 pretreatment also enhanced the migration and increased the secretion of pro-survival and angiogenic cytokines including basic fibroblast growth factor and vascular endothelial growth factor. Western blot and RT-PCR demonstrated that SDF-1 pretreatment significantly activated the pro-survival Akt and Erk signaling pathways and up-regulated Bcl-2/Bax ratio. These protective effects were partially inhibited by AMD3100, an antagonist of CXCR4.We conclude that the SDF-1/CXCR4 axis is critical for MSC survival, migration and cytokine secretion.
Assuntos
Animais , Masculino , Ratos , Apoptose , Proteínas Reguladoras de Apoptose , Genética , Metabolismo , Células da Medula Óssea , Metabolismo , Fisiologia , Hipóxia Celular , Movimento Celular , Quimiocina CXCL12 , Genética , Farmacologia , Fisiologia , Citocinas , Metabolismo , Expressão Gênica , L-Lactato Desidrogenase , Metabolismo , Sistema de Sinalização das MAP Quinases , Células-Tronco Mesenquimais , Metabolismo , Fisiologia , Proteínas Proto-Oncogênicas c-akt , Metabolismo , Ratos Sprague-Dawley , Receptores CXCR4 , MetabolismoRESUMO
This study was amied to construct CXCR4 gene modified bone marrow mesenchymal stem cells (MSCs), and investigate the effect of CXCR4 expression on MSCs migration. The retrovirus vector pMSCV-CXCR4-IRES-GFP that expresses human CXCR4 gene was cloned,the MSCs were transduced by the virus, and the expression of OXCR4 was analyzed by FACS, RT-PCR and immunofluorescence staining. The migration assay was performed using Transwell method in the presence of SDF-1. FACS results showed that 46% of the transduced MSCs were CXCR4 positive, and 57% were GFP positive. The expression of CXCR4 in MSCs was also confirmed by RT-PCR and immunostaining. The migration of MSCs was induced by SDF-1 and was strongly dependent on CXCR4 expression. The concentration of SDF-1 had effect on the migration and the transmigration rate of CXCR4 modified; the amount of MSCs was 5-fold higher than that of untransduced MSCs when the optimal concentration rose to 50 ng/ml. These data indicate that SDF-1/CXCR4 plays an important role in MSCs migration ,and the CXCR4 genetic modification approach could be applied to enhance cell homing, and engraftment in MSCs therapy.