Fate and protective effect of marrow stromal cells after subretinal transplantation

Engraftment of marrow stromal cells (MSCs) has been proposed as a therapeutic approach for degenerative diseases. In this study we investigated the fate and dynamic progress of grafted MSCs in living retina with the aim of evaluating the use of transplanted MSCs to treat retinal degeneration. Approximately 1×10⁵ gfp -MSCs in 2 μl phosphate-buffered saline were injected into the subretinal space of adult Sprague-Dawley rats. Two weeks later, approximately 0.174%±0.082% of the transplanted cells had survived and diffused into the subretinal space. Nine weeks after transplantation the surviving gfp -MSCs accounted for 0.049%±0.023% of the number of cells injected and were mainly located at the injection site. The same number of MSCs were transplanted into the left eye subretinal space of 3-week-old hereditary retinal degenerative Royal College of Surgeons rats, and phosphate-buffered saline was injected into their right eyes as a control. Five weeks after transplantation, the amount of rudimentary photo-receptors was more significantly increased in grafted eyes than in control eyes. The results indicated that grafted MSCs could survive and rescue retinal degeneration.