The effect of NGF gene modified Scwhann cells on DRG neurons repair after compressed injury

Abstract

Objective To study the effect and mechanism of NGF gene modified SCs on DRG (dorsal root ganglion) neurons repair after compressed injury.Methods SCs were obtained by one enzyme digestion method.SCs were transfected with NGF gene by adenovirus.Thirty-two female SD rats with compression injury of dorsal root ganglia on right lumbar nerve roots.were divided randomly into following groups:Normal saline (NS) group,Pure SCs group,Ad-NGF group,and SCs+NGF group.Nerve root tissues were harvested 2 weeks after treatment.Western blot were used to detect the proNGF volume in nerve root tissue lysis; Double-labeling fluorescent Immunohistochemistry (IHC) was used to count the number of β-Tubulin Ⅲ positive cells and activating transcription factor 3 positive cells.The ratio of injured neurons to survived neurons was calculated.Results Western bolt showed the proNGF volume in nerve root tissue lysis of SCs+NGF group increased dramatically.Double-labeling fluorescent IHC showed SCs+NGF group vs any group,the density of survived DRG neurons (β-Tubulin Ⅲ positive cells) increased significantly,meanwhile the percentage of injured neurons (ATF3 positive cells) in survived neurons decreased dramatically.Conclusion NGF gene Modified SCs could promote the survival of DRG neurons after compression injury and decrease the ratio of injured neurons.We conclude that this study provides a new treatment strategy for the patients who suffer from chronic compression injury on nerve roots and DRG neurons. Key words: Nerve growth factor; Schwann cells; Ganglia, spinal; Rats