Schwann-like cells differentiated from human dental pulp stem cells combined with a pulsed electromagnetic field can improve peripheral nerve regeneration

Abstract

The purpose of this study was to investigate the effect of Schwann-like cells combined with pulsed electromagnetic field (PEMF) on peripheral nerve regeneration. Schwann-like cells were derived from human dental pulp stem cells (hDPSCs) and verified with CD104, S100, glial fibrillary acidic protein (GFAP), laminin, and P75(NTR) immunocytochemistry. Gene expression of P75(NTR) and S100 were analyzed. Male Sprague-Dawley rats (200-250g, 6-week-old) were divided into seven groups (n=10 each): control, sham, PEMF, hDPSCs, hDPSCs+PEMF, Schwann-like cells, Schwann-like cells+PEMF. Cells were transplanted (1x10(6)/10 mu l/rat) at crush-injury site or combined with PEMF (50Hz, 1h/day, 1mT). Nerve regeneration was evaluated with functional test, histomorphometry and retrograde labelled neurons. Schwann-like cells expressed CD104, S100, GFAP, laminin, and p75 neurotrophin receptor (P75(NTR)). P75(NTR) and S100 mRNA expression was highest in Schwann-like cells+PEMF group, which also showed increased Difference and Gap scores. Axons and retrograde labeled neurons increased in all treatment groups. Schwann-like cells, hDPSCs with or without PEMF, and PEMF only improved peripheral nerve regeneration. Schwann-like cells+PEMF showed highest regeneration ability; PEMF has additive effect on hDPSCs, Schwann-like cell in vitro and nerve regeneration ability after transplantation in vivo. Bioelectromagnetics. 37:163-174, 2016. (c) 2016 Wiley Periodicals, Inc.