ABSTRACT
OBJECTIVE: This study was designated to determine the effect of cord blood cell transplantation in ischemic injury model. METHODS: In this study, we administered human umbilical cord blood (hUCB)-derived CD34(+) cells into the lateral ventricle or directly into the striatum and assessed cell migration in mice with cryoinjury and behavioral recovery in rats with transient middle cerebral artery occlusion (MCAo). CD34(+) cells were isolated by magnetic cell sorting using CD34-microbeads and labeled with CM-Dil. RESULTS: When CD34(+) cells were injected into mice brain with cryoinjury, cells were migrated into a injury site after one week of injection. Similarly, injected CD34(+) cells were migrated into the periphery of infarcted area in rats with transient MCAo. When spontaneous activity was measured using a modified neurological severity score (mNSS), it was found that functional recovery was significantly higher when CD34(+) human umbilical cord blood cell (hUCBC) was transplanted 24 hours after stroke compared with phosphate buffered saline (PBS)-injected or CD34(-) transplanted, stroked animals (P<0.05). Although only small portion of transplanted cells were differentiated into neural lineages, CD34(+) hUCBC transplantation increased Brdu incorporation and recruitment of doublecortin (DCX) (+) cells in ischemic boundary zone. CONCLUSION: These results suggest that hUCBC transplantation may be an effective treatment for brain injuries, such as stroke, or neurodegenerative disorders by promoting endogenous repair process of the brain.