Abstract
Purpose: :
The retinal pigment epithelium (RPE) is essential for visual cognition and nutrition of the outer retina. RPE dysfunction is a crucial event to age-related macular degeneration (AMD) and retinitis pigmentosa. To examine the availability of RPE dysfunction model by sodium iodate (SI) administered for the AMD study. Mesenchymal stem cell engraft into subretinal space of this model was tried for a new horizon to therapeutic strategy curing incurable diseases.
Methods: :
SI resolved in saline was administered into the peritoneal cavity of the rats in dose of 50 mg/ kg body weight twice with three days interval. DiI-labeled mesenchymal stem cells of 3 passages were applied into the subretinal space of the animals at 4 days after the final injection. RPE degeneration was evaluated by light and electron microscopy and stem cells were traced with immunofluorescent microscopy.
Results: :
RPE in the SI-administered retinas was nearly disappeared remaining the continuous basement membrane underneath the choroid. In scanty basal cytoplasm, the melanin pigments and residual bodies were remained. The SI-administered retinas were detached from the RPE remaining opened subretinal space. The outer segments of the photoreceptor cells were shorten. Apoptotic cells with pyknotic nuclei were observed in the outer nuclear layer (ONL) of the SI-administered retinas. Stem cells were largely remained in subretinal space. Some of the stem cells were migrated into the ONL however these migrated cells showed no differentiation into neuronal or glial cell types of the retina.
Conclusions: :
These results suggest that an SI-induced RPE degeneration model will be available for AMD pathogenic studies and more researches such as stem cell modification and development of cell carrier substances will be necessary for the stem cell application into subretinal space.
Keywords: age-related macular degeneration • retinal pigment epithelium • injection