Effects of SDF-1α/CXCR4 on vascular smooth muscle cells and bone marrow mesenchymal cells in a rat carotid artery balloon injury model

Bone marrow mensenchyme cells (bmscs) can differentiate into endothelial progenitor cells which then migrate to injured sites for the repair of neointima,and stromal cell-derived factor-1α (sdf-1α) can mediate the migration of cxcr4 expressing stem/progenitor cells to injured sites for pair. protein and mrna expression of sdf-1α and cxcr4 were determined by rt-pcr,western blot and elisa. immediately after common carotid artery balloon injury,the mrna expression of sdf-1α in vascular smooth muscle cells (vsmcs) first increased and then decreased 7 days later. vsmcs transfected with sdf-1α sirna did not express sdf-1α mrna,but after transfection with sdf-1α sirna,the sdf-1α content in injured vsmcs gradually returned to the baseline level. normal bmscs rarely expressed cxcr4 mrna,but the cxcr4 mrna expression on bmscs increased significantly 4 days after common carotid artery injury and was maintained. the migration of bmscs after artery injury was enhanced when compared with normal bmscs,but sdf-1α sirna transfection of vsmcs and amd3100 treatment remarkably decreased the chemotaxis of bmscs to vsmcs and sdf-1α,respectively. we conclude that the sdf-1α/cxcr4 axis plays an important role in the migration of bmscs after balloon injury and can ultimately cause abnormal proliferation of the intima.