Feasibility Study Of Adipose Derived Mesenchymal Stem Cells For Repairing Injuried Facial Nerve Of SD Rats

Background and objective:Facial palsy has brought great suffering to patients,and seriously impairs the quality of patient's life.How to treat intractable facial paralysis and recurrent facial paralysis is a major puzzle to the academic world,adipose-derived stem cells are non-specialized cells which have the ability of self-renewal and multiple differentiation potential.Adipose derived mesenchymal stem cells(ADSCs)have the characteristics of convenient material extraction,easy extraction and immune rejection.So ADSCs is a common osteogenic stem cells.There is no research about ADSCs for repair facial nerve injury.In this study,we firstly established a model of facial nerve injury in SD rats,and human adipose derived mesenchymal stem cells(hADSC)were injected into facial nerve injury.We studied that the feasibility study of hADSC for repair facial nerve injury,in additional,we explored the reason of hADSC for repair facial nerve injury on molecular mechanismMethodsIn the first part,we analyzed some clinical and epidemiologicaspects of Bell's palsy(BP)and to develop relevant correlationsbetween existing data in literature and those obtainedin this research.Second,the SD rat model of peripheral facial paralysis was established by extrusion of facial nerve.The model was verified and evaluated by behaviordetection,histopathology and electrophysiology.And we selected the best animal model.In the third part,selection,cultivation and identification of human adipose derived mesenchymal stem cells.The adipose tissue used in this study was obtained from healthy people in plastic surgery.The adipose tissue was digested and cultured,and the cells were identified in three aspects:morphological identification,value added cycle identification and cell phenotype identification.In the fourth part,we studied the expression of stromal cell derived factor(SDF-1)in facial nerve injury by immunohistochemistry and Western-blotting.In additional,we research the experiment of SDF-1 promoting hADSC migration in vitro by Transwell.In the fifth part,we focused on repair of the myelin sheath of SD rats and facial nerve repair by hADSC after facial nerve injury.After the hADSC transplanted into facial nerve,we observed the improvement of facial paralysis in SD rats at 3,7 and 14 days after operation in three aspects:morphological identification,value added cycle identification and cell phenotype identification.The latest part,we explored the molecular mechanism of human adipose derived mesenchymal stem cells repairing facial nerve injury.A paracrine effect and alleviate edema of facial nerve is the main molecular mechanisms.ResultsIn the first part,324(87.1%)subjects had BP for the first time(12.9%recurrence rate).Second,the injuried facial nerve in SD rats was evaluated by self-made quantitative injury forceps.The damage intensity is 50g and 80g respectively,the parameter was set to 80 grams for strength.In the third part,human adipose derived mesenchymal stem cells were successfully cultured.hADSC were observed under inverted microscope,Stem cell related surface markers such as CD13,CD29,CD44,CD105 were all positive,however,the CD31?CD34 were all negative.In the forth part,the expression of stromal cell derived factor(SDF-1)in facial nerve injury is higher than the normal facial nerve by immunohistochemistry and Western-blotting.SDF-1 promoting hADSC migration in vitro by Transwell.The number of hADSC migrating cells increased with the increase of stromal cell derived factor-1.In the fifith part,after the hADSC transplanted into facial nerve,we observed the improvement of facial paralysis in SD rats at 3,7 and 14 days after operation in three aspects:Behavioral score,Neurophysiology and neuropathology.In the final part,the results of immunohistochemistry(ICH)showed that the levels of brain-derived neurotropic factor and vascular endothelial growth factor in experimental group were significantly higher than those in control group at three time points.The result of western-blotting and RT-PCR were similar to ICH.Immunofluorescence showed that the expression of-1 in control group was significantly higher than that in group hADSC at third days and seventh days after operation.ConclusionThe injured facial nerve was highly expressed in SDF-1 protein,which can induce hADSC close to the injured facial nerve,and then participate in the repair of the injured facial nerve.