Derivation of Schwann cell precursors from neural crest cells resident in bone marrow for cell therapy to improve peripheral nerve regeneration.

We have previously successfully enriched post-migratory neural crest cells (NCCs) from postnatal rat bone marrow (BM). These BM-NCCs possess glial and neuronal differentiating potential. Based on the neural crest origin of Schwann cells (SCs), in this study, we aimed at using a straightforward protocol to derive Schwann cell precursors (SCPs) from BM-NCCs. Several clonal subpopulations were isolated from BM-NCCs, displaying long-term proliferative capacity and maintaining the NCC identity. The BM-NCC clones could be induced to differentiate into SCs. In particular, clone N1 gave rise to a large and pure population of SCs. Clone N1-derived SCs demonstrated the myelinating capacity in their co-culture with primary dorsal root ganglion (DRG) neurons. The decreased expression of NCC-markers and increased expression of SC-markers were related to the differentiation state of clone N1-derived SCs. To investigate the repair-promoting effects of clone N1 on injured peripheral neurons in vitro and in vivo, on one hand, the oxygen glucose deprivation-injured DRG neurons were treated with clone N1-conditioned medium, improving the cell survival and axon growth of neurons; on the other hand, clone N1 or clone N1-derived SCs were respectively implanted to the crush sciatic nerve of rats, and clone N1 yielded the better outcome of nerve regeneration and function restoration than clone N1-derived SCs. Taken together, all the results collectively showed that clone N1 could be identified as SCPs, which might hold promise for cell therapy to improve peripheral nerve regeneration.