ABSTRACT
Objective To investigate the effect of transplantation of human umbilical cord blood CD34+cells on spinal cord injury. Methods CD34+cells were separated from fresh human umbilical cord blood by magnetic cell sorting. Ninety-six female Wistar rats were injured at T10 by IMPACTOR MODEL-Ⅱ, and then randomly assigned to three groups:Cyclo?sporin A (CsA)+Dexamethasone (Dex) treated group (Ⅰ, n=32), local transplantation of cells+CsA+Dex treated group (Ⅱ) at the first day after operation (DAO 1, n=32), local transplantation of cells+CsA+Dex treated group (Ⅲ) at DAO 6 (n=32). BBB locomotor scoring system was used to assess the recovery of the lower limbs. The survival and neural differentiation of transplanted cells at the injury site were observed by double immunofluorescence. The tissue vitality at the injury site was ob?served by 2,3,5-triphenyl-2H-tetrazolium chloride (TTC) staining, and the blood vessel density was observed by infusing mixture of Chinese ink and glutin followed by HE staining. Results BBB score at DAO 8-56 was significantly higher inⅡgroup than that of other two groups (P<0.05). TTC staining showed that the proportion of decreased vitality area was signifi?cantly smaller inⅡgroup than that of other two groups (P<0.01). The result of gelatin ink perfusion showed that the blood vessel density at the injury site was significantly bigger inⅡgroup than that of other two groups (P<0.01). There were more survival transplanted cells inⅡgroup than those of III group (per visual field, 7.51 ± 1.00 vs 5.51 ± 0.89,t=6.051, P<0.01). All the transplanted cells didn’t differentiate into neural cells. Conclusion Human umbilical cord blood CD34+cells can promote the recovery of the lower limbs after spinal cord injury by repairing blood vessels to increase tissue vitality at the in?jury site in rats.
