Growth factors in mesenchymal stem cells following glial-cell differentiation.

Schwann cells are essential facilitators of peripheral nerve regeneration following injury, as they provide physical support and guidance. In vitro these supporting cells are slow-growing and hence are not well suited to a tissue-engineering approach to nerve repair. We have differentiated rat bone-marrow-derived mesenchymal stem cells into Schwann-cell-like cells using a cocktail of growth factors, including glial growth factor-2. Qualitative reverse transcription-PCR, Western-blotting and immunocytochemical approaches were used to investigate the mRNA transcript levels and protein expression of glial cell markers and neurotrophic factors in differentiated mesenchymal stem cells compared with the levels found in Schwann cells (which acted as a positive control). The results showed that differentiated mesenchymal stem cells expressed transcripts and proteins for the specific glial growth receptor 2, erbB3 and neurotrophic factors, nerve growth factor, brain-derived neurotrophic factor, glial-derived neurotrophic factor and leukaemia inhibitory factor. Expression of these growth factors provides further evidence that differentiated mesenchymal stem cells appear to have cellular and molecular characteristics similar to those of Schwann cells.