Transplantation of Retinal Cells Derived From Neonatal CAG–GFP or Nrl–GFP Transgenic Mice to Degenerated Mouse Retina

Abstract

Abstract: : Purpose: To evaluate the effect of the enzyme that degrades extracellular glial matrix on the cells transplanted to the degenerated retina. Methods: Dissociated retinal cells were prepared from neonatal CAG–GFP or Nrl–GFP transgenic mice. Each cell suspension from two lines with or without the enzyme that trims the carbohydrate side chains off large extracellular proteins was transplanted subretinally into the eyes of adult mice whose photoreceptors degenerated with intraperitneal injection of N–methyl–N–nitrosourea. They were sacrificed two or four weeks after transplantation and processed for immunohistochemical analysis. Results: Four weeks after transplantation, a part of the CAG–GFP⁺ retinal cells had migrated to the inner nuclear layer of the host retina, whereas the Nrl–GFP⁺ photoreceptor cells resided at the outer margin of the host retina where the photoreceptor layer had originally existed. Some of the Nrl–GFP⁺ photoreceptor cells elaborated neurites toward the host retina. This phenomenon was more evident when transplanted with the proteoglycan–degrading enzyme: The neurites elaborated from the Nrl–GFP⁺ photoreceptor cells extended over the glial seal at the graft–host interface and entered the host retina. Moreover, the neurites were immunoreactive for the synaptic vesicle marker, suggesting the establishment of synaptic contact between the grafted photoreceptor cells and the host retina. Conclusions: The current results suggest that the application of the enzyme that degrades extracellular glial matrix can enhance the robust integration of the transplanted cells into the photoreceptor–degenerated retina.

Keywords: transplantation