Xirradiationinduced loss of O2A progenitor cells in rat spinal cord is inhibited by implants of cells engineered to secrete glial growth factor 2

THE loss of O-2A progenitor cells has been implicated as a critical event in radiation-induced spinal cord demyelination. To investigate whether glial growth factor 2 (GGF2) affects the number of O-2A cells in the irradiated rat cervical spinal cord, an ex vivogene therapy approach was applied in which CHO cells engineered to express recombinant human GGF2 were injected into the cisterna magna of adult rats. Spinal cord irradiation reduced the number of O-2A cells in a dose-dependent manner. However, this radiation-induced decrease in O-2A progenitor cells was significantly attenuated by the delivery of GGF2 after irradiation. These data indicate that the cell-mediated delivery of GGF2 can reduce the loss of O-2A progenitors after irradiation.