Stromal cell-derived factor-1/CXCR4 effects on ex vivo expanded bone marrow mesenchymal stem cells migration

Background: Exogenous human mesenchymal stem cells (MSCs) possess an ability to selectively migrate to the site of injury, and may further repair various damaged tissue. The mechanisms of directional migration remain unclear. Objective: To examine the expression of the CXCR4 receptor in MSCs after long-term culture ex vivo, and to investigate the effects of stromal cell derived factor-1 (SDF-1) at various concentrations on MSCs migration. Methods: MSCs were cultured ex vivo to passage 10, and then cell senescence was determined by β-galactosidase staining. The expression of CXCR4 receptor in MSCs was examined by RT-PCR and immunofluorescence staining. Transwell system was used to detect in vitro migration capacity of MSCs towards SDF-1. Results and Conclusion: Proliferation gradually decreased in all samples in the course of long-term culture ex vivo, and became restricted to senescent stages at passage 6 or 7. The expression of CXCR4 receptor was gradually lost with culture expansion. SDF-1 induced the migration of MSCs in a dose-dependent manner.