Neuroprotector effect of adult mesenchymal stem cells in the early phases after spinal cord injury

Aim: To study if the intralesional administration of adult mesenchymal stem cells modifies the number of apoptotic nervous cells in the early phases after severe spinal cord injury (SCI). Material and methods: Twenty adult Wistar rats were subjected to SCI at dorsal level. Two hours after the lesion, in 10 animals a volume of 10 mu l of saline into the lesion were administered. Other 10 animalsreceived 10(6) bone marrow stromal cells obtained. Five animals of each group were sacrificed at the 8 hours after the lesion and the other 5 animals at the 72 hours. The spinal cord was processed in each animal for conventional histological studies and to identify cells in apoptosis using the marker Mab F7-26 (apostain). The number of cells in apoptosis with appearance of neurons or glial cells was quantified in each group, averaged and subjected to statistical comparisons. Results: In the control group the number of nervous cells expressing apostain was 138 +/- 16, at the 8 hours and 82 +/- 13 at the 72 hours after lesion. In the treated group the number of nervous cells expressing apostain was 76 +/- 11, at the 8 hours, and 57 +/- 7, at the 72 hours with statistically significant differences between the experimental groups. Conclusions: The intralesional administration of mesenchymal stem cells exercises an antiapoptotic effect in the precocious phases after severe SCI.