Objective To observe the effects of subretinal transplantation of rat mesenchymal stem cells (rMSCs) on Sodium Iodate (SI)induced retinal degeneration. Methods One hundred and twenty BrownNorway (BN) rats were divided into three groups including SI injection group,rMSCs transplantation group and normal control group, each with 40 rats. The retinal degeneration was induced by caudal vein injection of SI. The retinal pigment epithelium（RPE）and neural retinal were evaluated by ocular fundus photograph, fluorescein fundus angiography (FFA)，electroretinogram (ERG) and histological approach, and TUNEL（terminal deoxynucleotidyl transferasemediated dUTP nick end labeling ）. CMDiIprelabeled primary rMSCs were transplanted into the subretinal space of SIinduced rats. The survival, integration, and differentiation of rMSCs were observed between 14 day to 60 day after the transplantation.Results The rat retinal function was gradually reduced after14 days of SI injection, with a timedependent manner. After the RPE cells were damaged，the outer segments of photoreceptors became disrupted and shortened until karyopyknosis. The nuclear morphology and positive TUNEL labeling indicated that the death of photoreceptor cells was apoptosis. After rMSCs transplantation, CMDiI labeled donor cells were observed to be scattered in the subretinal space and expressed RPE cell markers. Average amplitude of b wave and Ops (oscillation potential) in ERG improved 27.80%,59.38% respectively after rMSCs transplantation.Conclusions Transplanted rMSCs can survive in subretinal space and differentiate into RPE.
Objective To observe the inhibiting effects of alginate sodiumretinoic acid（AGS-RA）microspheres release system on the laser coagulationinduced subretinal proliferation.Methods RA were dissolved by absolute alcohol,then mixed with 1.5% AGS and made into AGSRA microspheres by a microcapsule electrostatic generator. The parameter of laser injury include irradiation time (0.20 s)，spot diameter (200 mu;ｍ) and output power (420 ｍＷ).Thirty pigmented rabbits were randomly divided into 3 groups (laser injury，experimental and control group).After laser coagulation,AGSRA or blank microspheres were immediately injected into the vitrous of experimental and control rabbits respectively.The height,width and area of 6 retinal spots of laser coagulation at each timepoint were analyzed histopathologically with serial retinal sections at 1,2,3,4,and 6 weeks after laser coagulation.Results Histopathological examination showed that there were morphological and distribution changes of retinal cells in all layers, and localized fibroblasts proliferation in the retina after laser injury. The laserinduced responses in experimental group were much milder（P＜0.01）, while the laser injury group and control group have same width（P＞0.05）and height/area of laser spots（P＞0.05）.Conclusion AGSRA release system can alleviate the subretinal proliferate after laser injury.
Objective To investigate the feasibility of differentiation of invitro induced rat bone marrowderived mesenchymal stem cells（rMSCs） into retinal pigment epithelial （RPE） cells.Methods The rMSCs from BrwonNorway (BN) rats were isolated and cultured by adherent screening method. RPE cells lysate made by repeated freezethawing was put into the rMSCs culture system to identify whether the induced cells could express characteristic label cytokeratin（CK）and S-100 simultaneously or not.Results The growth rate of rMSCs induced by RPE cells lysate was slower and protuberant burr surrounded the fusiform cells. The results of immunoblotting and double immunofluorescence showed that partial induced cells expressed CK and S-100 simultaneously. The result of flow cytometry indicated that 14.1% induced cells expressed CK and S-100 simultaneously.Conclusion Induced by RPE cells lysate, rMSCs can differentiate into RPE cells.