Abstract: Objective To investigate the effect and its mechanism of H2O2 preconditioning-induced the enhancement of anti-apoptosis in BMSCs. Methods BMSCs isolated from rat were treated with H2O2 for 48h, or 50μmol/L H2O2 proconditioning following treatment with 500μmol/L H2O2 combined with or without anti-CXCR7 antibody for 48h. BMSCs viability was measured by MTT assay. The apoptotic cells was measured by Hoechst33342. The expression of SDF-1 and its CXCR4, CXCR7 receptor, Bcl-2, Bax and the key proteins of Akt/mTOR pathway was detected by Western blot. Results 25μmol/L and 50μmol/L was promoted markedly H2O2 BMSCs proliferation and the expression of SDF-1 and its CXCR4, CXCR7 receptor, and key phosphorylated proteins of Akt/mTOR pathway. Transwell migration assay and scraping result were shown that H2O2 preconditioning of BMSCs significantly augmented the migration ability, and protected BMSCs from 500 μmol /L H2O2-induced apoptosis，decreasing the rate of apoptotic cells, but antagonizing by anti-CXCR7 antibody. Conclusion H2O2 preconditioning induces the enhancement of the activity of bone marrow stem cell through CXCR7 receptor.

Key words: Bone marrow derived stromal stem cells(BMSCs), Hydrogen peroxide (H2O2), precondition, CXCR7 receptor, Cytoprotection