[EFFECTS OF BONE MARROW MESENCHYMAL STEM CELLS TRANSPLANTATION FOR TREATING RAT SPINAL CORD INJURY AND CYTOKINE EXPRESSION AT INJURY SITES]

Abstract

Objective: To investigate the effects of bone marrow mesenchymal stem cells (BMSCs) transplantation for treating spinal cord injury (SCI) in rat and the cytokine expression changes in the local injury tissues.

Methods: BMSCs were separated from Sprague Dawley (SD) rat and cultured with the whole bone marrow culture method. rAd-EGFP was used to transfect the 5th generation BMSCs for green fluorescent protein (GFP) label. Twelve SD rats were randomly divided into experimental group (n = 6) and control group (n = 6). After the T10 SCI model was established with Allen's impact device in 2 groups, 1 x 1096) GFP-labeled BMSCs and PBS were administered by subarachnoid injection in situ in experimental group and control group, respectively. Basso-Beattie-Bresnahan (BBB) score was used to detect the motor function at immediat, 1, 2, 3, 4, and 5 weeks after SCI. At 5 weeks, the spinal cord tissues were harvested for the histological and immunofluorescent staining examinations to measure the expressions of neural marker molecules, including Nestin, glial fibrillary acidic protein (GFAP), and neuron-specific nuclear protein (NeuN). Cytokine was analyzed with antibody array.

Results: At 5 weeks, 2 rats died of urinary tract infection in 2 groups respectively, the other rats survived to the end of experiment. BBB score of experimental group was significantly higher than that of control group at 1, 2, 3, 4, and 5 weeks (P < 0.05). At 5 weeks, histological results showed that there were many cells with regular arrangement in the experimental group; there were less cells with irregular arrangement in the control group. Compared with the control group, Nestin and NeuN expressions significantly increased (P < 0.05), and GFAP expression significantly decreased (P < 0.05) in the experimental group. Leptin and ciliary neurotrophic factor levels were higher in the experimental group than the control group, but granulocyte-macrophage colony-stimulating factor, tumor necrosis factor β, interleukin 1 β, and tissue inhibitor of metalloproteinases 1 levels were lower in the experimental group than the control group.

Conclusion: BMSCs transplantation can improve survival and regeneration of nerve cells and enhances the recovery of nerve function by regulating secretion of cytokines from grafted BMSCs.