Role of soluble NgR in promotion of DRG neurite sprouting in vitro in rats

Objective To observe the effect of soluble NgR on rat DRG neurite sprouting in vitro. Methods Gene encoding NgR(310)ecto was transduced into bone marrow stromal cells (BM-SCs). Soluble NgR was obtained from the supernatant of BMSCs culture. DRG neurons of neonate rat were isolated and allocated into two groups, ie, control group (DRG neurons were cultured in slides coa-ted with myelin protein of spinal cord) and experiment group (the slides were pre-incubated with the su-pernatant of BMSCs for four hours). BMSCs were immobilized after 24 hours of culture. Immunohis-tostaining with βⅢ-tubulin and fluorescence microscope were employed to analyze the neurite growth.Results Positive staining of intracytoplasm was found with indirect fluorescence microscope in the BM-SCs 48 hours following transduction. Little neurite was found sprout to DRG neurons in the control group 24 hours after transduction. In contrast, longer neurite was observed in about 60% neurons in the experi-ment group. Conclusion Soluble NgR can competitively bind to the inhibitory factors secreted local-ly, protect physiological NgR and promote axonal regeneration and functional recovery of the spinal cord following spinal cord injury. Key words: Ganglion,spinal; Regeneration; Bone marrow stromal cells