Rat Bone Marrow Mesenchymal Stem Cells In The Choroidal Neovascularization Microenvironment In The Differentiation Experimental Research

Objective To access the differentiation of subretinal-transplanted rat mesenchymal stem cells (MSCs) in the microenvironment of choroidal neovascularization (CNV) and changes of CNV exudation after the transplantation .Methods In-vitro cultured Brown Norway (BN) rats MSCs were identified CD90(+) CD45(-)by flow cytometry and labeled with Brdu. 25 CNV rats models were established by Krypton laser photocoagulation and subsequently confirmed by fluorescein angiography(FA). 25 rats were randomly distributed into 5 groups, 5 rats in every group. The right eyes were injected with MSCs into subretinal space, while the left eyes were injected with the same amount of PBS. The rats were killed and globes enucleated 1,2,3,4 or 5 weeks after the surgery respectively. Frozen sections were stained with Brdu primary monoclonal antibody, FITC- labeled secondary monoclonal antibody and CD31 , rhodopsin or pan- cytokeratin(PCK) primary monoclonal antibody respectively combined with Cy3-labeled secondary monoclonal antibody . The sections were observed under fluorescent microscope. Calculate and compare the exudation areas change pre-and post-transplantatively by FA.Results MSCs distributed on the surface of CNV in the 1^st week after surgery with CD31 negative.However, from the 2^nd to 5^th week, CD31 positive MSCs were found in CNV. Rhodopsin positive and PCKpositive MSCs were found near CNV in the 5^th week. FA analysis demonstrated a mild decrease tendency of CNV exudation after the transplantation of MSCs.Conclusions The results demonstrates that MSCs have the potential to differentiate into endothelium from 2th to 5^th weeks, into photoreceptor cells and RPE in 5^th weeks after subretinal transplantation in the microenvironment of NCV.CNV exudation may be mildly improved after subretinal transplantation of MSCs.