Investigation In The Potential Role Of Dorsal Root Ganglia Derived Precusor Cells In Repairment Of Spinal Cord Injury

[Background]:With the rapid development of modern industry and transportation, the incidence of traumatic Spinal cord injury (SCI) has showed an increasing trend over time, causing serious debilitating disorder that results in complete or partial loss of motor/sensory and autonomic neuronal functions, that was brought tremendous economic and psychological burden for individual and family of throughout the community. Several different clinical treatment strategies such as operation, drug intervention (steroidal, neurotrophic, dehydration), and other physical therapy have been tested for successful clinical treatment. Although the various therapeutic strategies are employed for the treatment of spinal cord injury, until now there is no proper and satisfactory cure for spinal cord injury patients. Therefore, neural repairment and regeneration have been the hot issues in academia research for spinal cord injury.Currently, cells therapy hold a great promise treatment in neural repairment of spinal cord injury. Searching for proper and appropriate regeneration donor cell was a focus in the field of cell research. However, dorsal root ganglia (DRG) precursor cells remain to be less considered, which have the ability of self-proliferation and multiple differentiation in the previous researches. It has been unclear whether dorsal root ganglia precursor can be applied to the treatment of spinal cord injury. [Objective]:To investigate the proliferation and differentiation potential of precursor cells in dorsal root ganglia in vitro, and then in vivo precursor cells transplanted into a spinal-cord hemisection-injury rat model to explore their role on the functional recovery in neural repairment of spinal cord injury. [Materials and Methods]:Neural precursor cells of dorsal root ganglia were obtained from embryo rats, and then sing cell suspensions were achieved by double enzymatic digestion method. The proliferation potential of precursor cells in stem cell culture medium was detected optical density of cell suspensions by CCK-8 kit. With the induction of differentiation reagents, the proportion of multi-pluripotent differentiation toward neuronal cells was determined by immunofluorescent staining. Under the condition of recombinant adeno-associated virus as a vector, precursor cells labeled with green fluorescent protein were injected into spinal-cord hemisection-injury rat model as the experimental group; the control group received equivalent saline injection. The migration and differentiation of precursor cells in vivo were detected by immunofluorescence and the neurological function recovery of injured rats evaluated by Basso, Beattie and Bresnahan (BBB-21) score at 1,4,6 weeks after cell transplantation. Data was statistically were analyzed by One-Way Analysis of variance (ANOVA), and the difference (p<0.05) was considered statistically significant.[Results]:In vitro, the high purified neural precursor cells of dorsal root ganglia were gained from sing cell suspensions which was obtain by double enzymatic digestion method. Under the condition of stem cell culture medium, The self-proliferation potential of precursor cells like neural stem cells was confirmed by CCK-8 kit. With the differentiation-inducing reagents, most precursor cells differentiated into glial cells on induction; only a few precursor cells differentiated into neuronal cells. In vivo, when virus labeling precursor cells were injected into spinal-cord injury model, the BBB-21 score was higher in the experimental than control group at 1,4, and 6 weeks after precursor cell transplantation, and the difference was considered statistically significant by One-Way Analysis of variance (p<0.05). Precursor cells could establish extensive connections with host neurons by immunofluorescence staining;[Conclusions]:In vitro, the proliferation and differentiation potential of DRG neural precursor cells were confirmed under the specific condition, and the precursor cells can mostly differentiate into glial cells. In vivo, with the virus labeling precursor cells transplanted into spinal-cord injury model, the cells can survive in the injury site, especially differentiate into glial cells. Precursor cell transplantation can promote nerve functional recovery, which was establish extensive synaptic connections with host neurons.