Selective engraftment of bone marrow stromal cells in lumbar dorsal root ganglia and spinal cord from rats subjected to sciatic nerve lesion

M.F. CORONEL; P.L. MUSOLINO; M.J. VILLAR

Washington DC, USA

Congreso; Society for Neuroscience; 2005

Society for Neuroscience

Bone marrow stromal cells (MSCs) have been demonstrated to preferentially migrate into the injured hemisphere of rats subjected to a traumatic brain injury and improve the functional outcome of these animals. We now demonstrate that the intravenous administration of MSCs in rats subjected to a sciatic nerve lesion results in selective engraftment of the cells, not only in the lesioned nerve, but also in the ipsilateral lumbar dorsal root ganglia (DRG) and spinal cord (SC). Whole marrow was aspirated from the tibiae and femurs of Sprague-Dawley rats, the mononuclear cells were isolated using a density gradient and plated at a concentration of 2-3 x 106 cells/ml in DMEM, 10% FBS in 25 cm2 cell culture flasks. MSCs were isolated by their adherence to plastic, cultured until they reached confluence, labeled with Hoechst 33258 and harvested using trypsin- EDTA. 1-2 x 106 cells were injected in the tail vein of adult Sprague-Dawley rats that had been subjected to a sciatic nerve lesion (crush or axotomy) 2, 5, 7 or 14 days before. The animals were perfused through the heart after 2, 7 and 14 days pos transplantation and the ipsi and contralateral sciatic nerves, lumbar 4-5 DRGs and the corresponding levels of the SC were dissected out. The tissues were cut and observed using a fluorescence microscope. MSCs were detected not only at the site of injury in the lesioned nerve, but also in the ipsilateral lumbar DRGs and SC, showing an active migration of MSCs from the vascular tree, followed by a selective engraftment of these cells in the lesioned neural tissues. These results provide evidence for a possible regenerative role of these cells, not only at the lesion site (sciatic nerve), perhaps related to myelin recomposition, but also at a neural level both in DRGs and SC. Further studies should be carried out in order to evaluate the contribution and mechanisms of MSCs to peripheral nerve regeneration.