Effects Of Combining Olfactory Ensheathing Cells And Methylprednisolone On The Recovery Of Neurological Functions And The Expression Of Nogo-A After Acute Spinal Cord Injury In Rats

Object:To investigate the effectiveness of combining Olfactory ensheathing Cells and large dose methylprednisolone after acute spinal cord injury in rats on nogo-A expression and recovery of neurological functions and its mechanism.Methods:OECs were harvested and purified following a previously described Nash's technique. Briefly 126 female adult Sprague-Dawley rats were randomized into 6 groups:normal group(n=6),sham-operated group(n=24) ,SCI group(n=24),SCI+OECs-treated group(n=24), SCI+MP-treated group(n=2), SCI+OECs+MP- treated group(n=24). Rats acute spinal cord injury model was established with modified Allen's method. Olfactory ensheathing Cells were labeled by Dapi before the transplantation. Soon after spinal cord injury(SCI),5×105 cells were injected into the injury area,and MP was administered for 24 hours. Before sacrificed and at 1d,3d,7d and 14d after SCI,Neurological functions were evaluated by using the Basso- Beattie-Bresnahan(BBB); The nogo-A was detected by the immunohistochemical method, reverse transcriptase-polymerase chain reaction (RT-PCR) were used to measure the expression of nogo-A at 1d,3d,7d and 14d after SCI.Results:Dapi staining positive cells were observed around the injury area in OECs-treated group and OECs+MP-treated group. By compared with control group, SCI+OECs-treated group and SCI+MP-treated group,the neurological functions were better in SCI+OECs+MP-treated group at 7d,14d after SCI(P<0.05),There was no significant differences of the BBB's score at 1d,3d,7 d and 14 d post SCI between SCI+OECs-treated group and SCI+MP-treated group; nogo-A around the injury area was significantly downregulated at 3d,7d,14d after SCI. (all P<0.01). There was no significant differences of neurological functions in rats'spinal cord at 1d and 3d post SCI among all groups mentioned above(P>0.05).Conclusions:1,Combining OECs and MP after acute spinal cord injury in rats can significantly improve the neurological functions , and its Mechanism was partly related to downregulate nogo-A expression.2,When used in combination , OECs and MP have better effect on the neurological functions recovery,which suggest that OECs and MP may have synergistic effects.