Fat tissue, a potential Schwann cell reservoir: isolation and identification of adipose-derived Schwann cells.

Schwann cells can be used to promote peripheral nerve repair. However, it is challenging to obtain abundant autologous Schwann cells without sacrificing nerve integrity. In this study, we isolated Schwann cells from murine inguinal adipose tissue and identified the cell phenotype and function in vivo and in vitro. Through H&E and immunofluorescence staining, we detected tiny nerve fibers and Schwann cells in adipose tissue. We evaluated the phenotype of spindle-shaped cells (Schwann cell-like cells, SCLCs) isolated from adipose tissue using immunofluorescence staining and real-time RT-PCR. The results showed that SCLCs expressed specific Schwann cell markers. Analysis of conditioned SCLC culture media showed that, similar to Schwann cells isolated from sciatic nerves, SCLCs secreted NGF and BDNF. SCLCs were harvested from CAG-EGFP transgenic mice and combined with silicone nerve conduits to repair sciatic nerve defects in wild-type mice. Six months post-surgery, we found EGFP-positive SCLCs forming myelin sheaths in the same way as sciatic nerve-derived Schwann cells. This research indicates the existence of Schwann cells in adipose tissue and identifies the spindle-shaped cells isolated from adipose tissue as Schwann cells using in vitro and in vivo evaluations. Thus, SCLCs might be promising seed cells for peripheral nerve tissue engineering.