Brain-derived neurotrophic factor suppresses anoikis-induced death of Schwann cells

Anoikis is a type of apoptosis due to the detachment from the extracellular matrix and neighboring cells. In case of cell transplantation therapy for spinal cord injury, preparation of graft cells includes dissociation of cultured cells, which may cause anoikis-induced cell death. Thus suppression of anoikis may increase survival of grafted cells. Here we tested the effect of brain-derived neurotrophic factor (BDNF) on anoikis-induced cell death of cultured Schwann cells. Schwann cells were collected and cultured from sciatic nerves of neonatal Wistar rats. Schwann cells were plated upon a non-adherent polyhydroxyethyl methacrylate substrate to induce anoikis. BDNF was added into the culture medium at various concentrations. Twenty-four hours after non-adherent culture, approximately 40% of Schwann cells died and BDNF significantly decreased the number of dead cells in that culture condition. Next, Schwann cells were transplanted with or without BDNF treatment into contused rat spinal cord 1 week after injury. Five weeks after transplantation, immunohistochemistry revealed that the number of transplanted cells was significantly larger in the BDNF-treated group than that of the non-treated group. Suppression of anoikis may increase survival of grafted cells in case of cell therapy for spinal cord injury.