Abstract
Purpose: :
To examine the effects of embryonic stem cell transplantation into eyes of a mouse model of retinal degeneration
Methods: :
Mouse embryonic stem cells (ESCs) labeled with the Yellow Fluorescent Protein (YFP) were grown in vitro and induced into neural progenitor cells. Eyes from mice containing the Rpe65/rd12 mutation were treated with intravitreal injections of ESCs or ESC–derived neural progenitor cells. At several time points starting at two weeks after injection, the animals were euthanized and eyes examined for presence of transplanted cells by light microscopy, fluorescent microscopy, and immunohistochemistry on both whole mount retinal preparations and retinal cross–sections. Fate and differentiation potential of the transplanted cells were also investigated by determining the expression of cell–specific genes and the YFP gene using RT–PCR.
Results: :
A total of 12 eyes from mice homozygous for the Rpe65/rd12 mutation were transplanted with either undifferentiated mouse embryonic stem cells (group A) or neural progenitor cells (group B). At two weeks following transplantation, both types of transplanted cells (A and B) were present in treated eyes. Only a small percentage of transplanted cells survived the procedure. Transplanted cells were found in the vitreous, as sheets of aggregated cells along the inner retinal surface, and as individual cells within different layers of the retina. Survival, proliferation, and differentiation of transplanted cells were also examined at eight weeks and fifteen weeks following injection.
Conclusions: :
Following transplantation into the vitreous cavity, ESCs and ESC–derived neural progenitor cells can survive and integrate into the retina of mice containing the Rpe65/rd12 mutation.
Keywords: transplantation • retinal degenerations: hereditary • transgenics/knock-outs