Remyelination of demyelinated rat spinal cord model by transplanting neural stem cells

ABSTRACT

Demyelination of CNS axons occurs under pathological conditions such as multiple sclerosis and spinal cord injuries, but can be repaired by cell therapy. Within the CNS remyelination can be achieved by transplantation of neural stem cells [NSCs]. NSCs are self-renewing cells that maintain the capacity to differentiate into CNS-specific cell types and can differentiate into the three main neural phenotypes astroglia, oligodendroglia and neurons. They may also replace or repair diseased CNS tissue. Bone marrow stromal cells [BMSCs] were aseptically isolated from the tibia and femurs of young adult Sprague Dawley rats. BMSCs were evaluated by fibronectin and CD31 markers. BMSC-derived NSCs were evaluated by nestin and NF-68. An ethidium bromide-induced demyelinated dorsal column lesion was produced in young adult rats. Transplanting NSCs derived-BMSCs into demyelinated lesions after 3 days in adult rat spinal cords was done. Three weeks after transplantation of NSCs, the spinal cords were processed to evaluate remyelination by Luxol fast blue staining. After passage 3, BMSCs were evaluated and the result, showed the percentage of immunoreactive cells to fibronectin [94.7 +/- 2.65], however BMSC-derived NSCs expressed nestin [86.15 +/- 0.64] and NF-68 [84.55 +/- 0.94] which correlated with fibronectin down regulation. Histologically, the lesions showed slightly irregular elongated areas and had an average length of 1336.36 +/- 39.43 microm. Transplanted NSCs were capable of eliciting remyelination. These data support the conclusion that transplantation of NSCs results in functional remyelination of a dorsal column lesion and have valuable applications in the treatment of neurodegenerative diseases such as spinal cord injuries