Human Umbilical Cord Blood Infusion in Paralyzed Rats: Histologic and Behavioral Alterations / 대한척추외과학회지

ABSTRACT

STUDY DESIGN: Experimental animal study OBJECTIVES: To examine the ability of human umbilical cord blood (hUCB) stem cells to target a zone of injury and to determine the efficacy of hUCB cells to ameliorate the behavioral deficits after a hUCB cell infusion in paralyzed rats. SUMMARY OF LITERTURE Many groups have investigated the use of stem cells as potential treatments for a CNS injury. hUCB cells have recently been reported to alleviate the behavioral consequences of a stroke injury. MATERIALS AND METHODS: Thirty Sprague Dawley rats were divided into 6 groups (Gr) (Gr 1. SCI (spinal cord injury) + hUCB delivered at one day postinjury, Gr 2. SCI + hUCB delivered at 3 days postinjury, Gr 3. SCI + hUCB delivered at 5 days postinjury, Gr 4. laminectomy + hUCB, Gr 5. SCI only, Gr 6. Laminectomy only). SCI was produced by compressing the spinal cord to the level of the 8-9th thoracic spine for 1 minute with an aneurysm clip that was calibrated to a closing pressure of 50 gms. The hUCB cells (0.5 ml, 1.5x106) were administered intravenously to the rats. The rat was assessed behaviorally at one, two and three weeks using the BBB behavioral scale. Four weeks after the injury, the animals were sacrificed and the hUCB positiveresponse neural cells (mouse anti-human mitochondria monoclonal antibody=MAB 1273) at the injury level observed using optical and fluorescent microscopy. RESULTS: MAB 1273 positive cells were observed in groups 1, 2 and 3 but not in groups 4, 5 and 6. In particular, there were 870 cells distributed over an area of 1.2 mm(2) in group 3. Group 3 showed the most significant recovery over time in the open field exam, and the most improvement in another tests of incline, leg extension, and toe spread compared with group 1 (p<0.01). CONCLUSION: After infusing the hUCB stem cells to SCI rats, it was confirmed that hUCB cells migrate to an injured area and ameliorate the behavioral deficits. A hUCB infusion 5 days after the injury produced best results in terms of the number of cells and motor recovery.