Combinatorial expression of glial transcription factors induces Schwann cell-specific gene expression in mouse embryonic fibroblasts.

Background: Schwann cells provide peripheral nerve trophic support, myelinate axons, and assist in repair. However, Schwann cell repair capacity is limited by chronic injury, disease, and aging. Schwann cell reprogramming is a cellular conversion strategy that could provide a renewable cell supply to repair injured nerves. Here, we developed a plasmid-based approach to test the Schwann cell conversion potential of four glial transcription factors.

Results: We employed four transcription factors implicated in Schwann cell differentiation and repair: Sox10, Sox2, Jun, and Pax3. Expression vectors were generated for Sox10 alone and two triple transcription factor combinations: Jun-Pax3-Sox2 (triple 1, T1) and Sox10-Jun-Sox2 (triple 2, T2). Mouse embryonic fibroblasts (MEFs) were transfected with these vectors, transferred to glial inductive media, and Schwann cell-marker expression was in assessed by immunostaining, flow cytometry, and qPCR. All expression vectors repressed fibroblast-specific gene expression. However, T2 was most efficient at generating O4⁺ Schwann cell-like cells, which had some capacity to myelinate denervated axons from explanted dorsal root ganglia. In comparison, T1 more efficiently induced repair Schwann cell-marker expression in converted O4⁺ cells.

Conclusions: T1 and T2 convert MEFs to Schwann cells with different efficacies and gene expression profiles, and may provide cell-based therapies for peripheral nerve repair.