Bone Marrow-derived Stem Cells Can Differentiate into Retinal Neural Cells in Injured Rat Retina and in Pigmentary Retinal Degeneration Rats

Abstract

Abstract: : Purpose: It has recently been shown that bone marrow cells can differentiate into various lineage cells, including neural cells in vitro and in vivo. We therefore examined whether bone marrow stem cells can differentiate into retinal neural cells in adult rats. Methods: Experiment I; PKH-67-labeled partially purified bone marrow stem cells (BMSCs) were injected into the vitreous space of eyes in which the retinas had been mechanically injured using a hooked needle. Two weeks after the injection of these cells, immunohistochemical examinations were carried out. Experiment II: N-methyl –N-nitrosourea (MNU) was injected into the rats to induce a pigmantary retinal degeneration. One week later, pigmantary retinal degeneration rats was produced, and PKH- labeled BMSCs were injected into the subretinal space of the rats to treat pigmantary retinal degeneration model rats. Two weeks after the injection of these cells, immunohistochemical examinations were carried out. Results: Experiment I; The BMSCs had been incorporated and had differentiated into retinal neural cells in the injured retina (86%: 5/6 eyes). The BMSCs had accumulated mainly in the outer nuclear layer (ONL) around the injured sites. The incorporated cells expressed glial fibrillary acidic protein (GFAP), calbindin, rhodopsin, and vimentin. Experiment II; The BMSCs had been incorporated and had differentiated into retinal neural cells in the pigmentary retinal degeneration rats (13%: 2/15 eyes). These findings strongly suggest that BMSCs have the capacity to differentiate into retinal neural cells, and that the injection of BMSCs into the retina would become a valuable strategy for the treatment of patients with retinal disease.

Keywords: regeneration • retina