Transplantation of expanded endothelial colony-forming cells improved outcomes of traumatic brain injury in a mouse model.

BACKGROUND: Endothelial progenitor cells (EPCs) are critical for repairing injured tissue. Endothelial colony-forming cells (ECFCs) are a homogeneous subtype of EPCs. We investigated whether intravenously infused human ECFCs homed to injured brain promoted angiogenesis and ameliorate neurologic disabilities in a mouse model of traumatic brain injury. MATERIALS AND METHODS: ECFCs were generated by in vitro propagation of EPCs from human umbilical cord blood. Young female nude mice received intravenously ECFCs from human newborns (1 × 10(6)) 1 h after they were exposed to lateral fluid percussion injury. Neurologic function was evaluated by a modified neurologic severity score and Morris water maze. ECFC homing and neovascularization at the site of injury were examined by fluorescence in situ hybridization and histochemistry on days 2 and 14 after injury, respectively. RESULTS: Donor ECFCs were detected in injured brain 24 h after infusion. The modified neurologic severity score and Morris water maze tests were used to evaluate neurologic disability, and found the rate of neurologic disability was improved in mice that received ECFCs. Microvessel density and expression of the proangiogenic growth factors stromal cell-derived factor-1 and vascular endothelial growth factor were also increased in the region of injured brain from mice that received ECFCs compared with those received vehicle control. CONCLUSIONS: These data suggest that ECFCs are effective in promoting neovascularization and improving neurologic functions after traumatic brain injury.