The Effects Of Neural Stem Cells And BFGF On Neurological Recovery After Spinal Cord Injury

Objective To establish the methods of isolation, cultivation and expansion in vitro of SD rats embryonic neural stem cells; To explore the effects of basic fibroblast growth factor ( bFGF) or/and neural stem cells (NSCs) on neurological recovery after spinal cord injury, and the possible mechanisms of neurological recovery after transplantation.Methods Unicellular suspension was obtained from the embryonic 16~ 18 days brain tissues by dissociating enzymatically and mechanically. A serum free medium (DMEM/F12) containing bFGF and B27 was used to culture, expand and passage NSCs in vitro.Immunocytochemistry was used to identify expression of nestin (maker for NSCs), NSE (maker for neurons), GFAP (maker for astrocytes) and GC (maker for oligodendrocytes). 65 SD rats were randomized to five groups: normal (Group A, n=13), and injury (Group B, Group C, Group D and Group E; Given T12 laminectomy with spinal cord left-hemisection, each group n=13); Group B was control group (given saline in injured spinal cord), Group C (given NSCs), Group D(given bFGF) and Group E (bFGF and NSCs were transplanted into rats' injured spinal cord) were transplanted groups. Immunohistochemistry of iNOS and c-fos were detected in every group at 2 hours after injury. Modified Combined Behavioral Scores (CBS) were assessed by blinder observers at 1,2,3 and 4 weeks after surgery.Results After adhesion NSCs could differentiate into NSE, GFAP and GC positive cells respectively. The cells derived from the cortex of SD embryonic rats show the capabilities of proliferation,self-renew and mutipotential differetiation, which are the characteristics of neural stem cells. The expression of iNOS and c-fos reduced at 2 hours after injury. Expression of iNOS and c-fos between Group B and Group C, D or E were significant difference (P<0.05), and showed significant difference between Group E and Group C or D (P<0.05). The CBS of group A waszero. Certain neurological recovery occur in Group B,C,D,E at 1,2,3,4 weeks after hemisection. CBSshowed significant difference between Group B or E and Group C or D (P<0.05) , The CBS was nosignificant difference between Group C and Group D.Conclusion The cells obtained from the cortex of SD embryonic rats were NSCs; Theneurologic function recovery were significantly improved in transplanted groups, Group E inparticular;We suggest here that, there is relationship between neurologic recovery and reducedexpression of iNOS and c-fos.