Abstract
Purpose: :
To assess the integration, maturation and survival of post-mitotic rod precursor cells transplanted into the subretinal space of the rd9 mouse, a spontaneously occurring mutant exhibiting X-linked pattern of retinal degeneration, as a function of host age.
Methods: :
Whole retinas from P4 Nrl -GFP mice were dissociated and transplanted into the subretinal space of rd9 mice of multiple ages (from 2 months to 10 months). Histology, immunohistochemistry and integrated cell counts were performed at different stages up to 4 months after transplantation.
Results: :
GFP-positive rod precursors were able to integrate into the outer nuclear layer (ONL) of the rd9 retina. Transplanted cells underwent morphologic maturation with formation of inner and outer segments and synaptic projections to bipolar cells. Integration of donor cells into the ONL increased as a function of host age. The number of integrated cells was maximal at 4 weeks post-transplantation and then decreased with time.
Conclusions: :
Our data suggest that the degree of integration of transplanted rod precursor cells into degenerating retinas varies with the age of the host. Further work is needed to define the mechanisms controlling donor cell survival after transplantation and to increase the efficacy of integration and functional assessment.
Keywords: photoreceptors • transplantation • retinal degenerations: cell biology