Local Upregulation of Stromal Cell–Derived Factor-1 After Ligament Injuries Enhances Homing Rate of Bone Marrow Stromal Cells in Rats

In the present study the local expression of stromal cell-derived factor-1 (SDF-1) after ligament injury and correlated change in the homing rate of systemically induced bone marrow stromal cells (BMSCs) to the injured site were clarified using a rat medial collateral ligament (MCL) injury model. SDF-1 was temporarily upregulated peaking at 2 weeks after injury. Correlated with the alteration in SDF-1 expression, the homing rate of systemically induced BMSCs was temporarily upregulated peaking at 2-4 weeks after injury. The SDF-1 expression in the MCL seems to play a crucial role in cell homing. In addition, SDF-1 did not influence the BMSCs behavior in vitro in terms of the proliferation, adhesivity, and expression of ligament fibroblast markers. The cell-based therapy for ligament and tendon injury with reference to local expression of SDF-1 may be one of the available applications.