ABSTRACT
Background Retinal ichemic-reperfusion injury (RIRI) affects vision and life quality and has no ideal treatment outcome up to now.The mechanism of RIRI is associated with apoptosis.Researches showed that subretinal transplantation of bone mesenchymal stem cells (BMSCs) can relieve RIRI,but its mechanism is unclear.Objective This study was to observe the influence of BMSCs subretinal transplantation on the expressions of apoptosis protein Fas/FasL,caspases-3 after RIRI,and to explore the neuroprotecitve mechanism of BMSCs transplantation to treat RIRI.Methods Bone marrow was isolated and extract form femur and tibia of SD rat by the density gradient centrifugation method and then the BMSCs were collected.BMSCs suspension was prepared using DMEM containing low-glucose with the cell density 1 x 106-2× 106/ml.RIRI models were established by ligation of optical nerve (Daniel M method).Sixty-four SD rats were randomly divided into the normal control group,model control group,BMSCs transplantation group and PBS control group.Twenty-four hours after RIRI,BMSCs suspension with the cells density 5× 104 cells was subretinally injected in the rats of the BMSCs transplantation group,and equal volume of PBS was injected in the same way in the rats of the PBS control group.The expressions of Fas/FasL and caspase-3 were dynamically detected using immunohistochemistry at 6,24,48 and 72 hours after BMSCs transplantation.Results The positive response cells for Hoechst33324 were seen in subretina 72 hours after BMSCs transplantation.A few of positive cells for Fas,FasL,caspase-3 proteins were expressed in the rats of the normal control group at 6,24,48 and 72 hours after BMSCs transplantation.However,the positive cells for Fas,FasL,caspase-3 protein were significantly increased in the model control group and the BMSCs transplantation group compared with the normal control group at various time points after injection (all at P＜0.01),and the number of positive cells was significantly less in the BMSCs group than those of the RIRI group and the BMSCs transplantation group (P＜0.05,P＜0.01).No significant differences were found in the numbers of positive cells of Fas,FasL and caspase-3 proteins at various time points between the model control group and the PBS control group (all at P＞0.05).Conclusions The subretinal transplantation of BMSCs down-regulate the expression of Fas/FasL and caspases-3 proteins in RIR1 rats,and thus alleviate the apoptosis of retinal neural cells.