OBJECTIVETo investigate the possibility of repairing spinal cord injury by bone marrow stromal cell (MSC) transplantation and microinjection of chondroitinase ABC (ChABC) in adult rats.

METHODSMSCs isolated from the femoral and tibial bones of new-born Wistar rats were cultured and the cell density was adjusted to 1×10(5)µl before transplantation. SD rats with T8 spinal cord crush injury were divided into 4 groups, namely group A (control) and groups B, C and D with injections of the MSCs, ChABC and MSCs+ChABC at the injury site, respectively. At 0 h, 1 day, 2 days, 3 days, 1 week, and 2 weeks after the injury, the BBB score system was used to evaluate the motion function. At 14 days after the injury, the maximal transverse diameter and actual area of necrosis were evaluated on HE stained sections. GFAP-CS56, GFAP-GAP43 and GFAP-NF160 immunofluorescence double labeling staining were carried out to evaluate the regeneration of the nerve fibers.

RESULTSAt the 14th day after the injury, BBB scores showed significant differences between group A and groups B, C and D (P<0.05), between the groups B and D and between groups C and D, butnot between groups B and C. HE staining showed cavity formation at the injury site in each group, with significant differences between group A and groups B, C and D and also between the latter 3 groups. Immunofluorescence staining revealed more intense expression of GFAP in group A than in the other groups with apparent cavity formation at the lesion site, which was only moderate in groups B and C. The expression of GAP-43 was more intense in group D than in groups B and C. The expression of NF-160 was more intense in group D than in the other 3 groups.

CONCLUSIONThe strategy of MSC transplantation combined with ChABC can be effective for repairing spinal cord injury in adult rats.