New mouse models of retinal degeneration

Researchers affiliated with the Kawasaki INnovation Gateway at SKYFRONT, have developed new mouse models of retinal degeneration enable transplantation of retinal sheets derived from human embryonic stem cells. The results of  the study  reported  in Stem Cell Reports  show the researchers approach to be promising for the treatment of retina degeneration by transplanting retinal tissue derived from embryonic or induced pluripotent stem cells.     In the study by Motohito Goto, Central Institute for Experimental Animals, Animal Resources and Technical Research Center, Kawasaki, Japan, and colleagues, two mouse models developed using marker-assisted breeding were presented and characterized. In the two models, the photoreceptor degeneration proceeded at different speed. The researchers transplanted retinal sheets derived from human embryonic stem cells in one of the models, characterized the structure of the transplanted retina and of the host-graft interface and measured the response to light. The retinal sheets were integrated for a long period of time, and showed signs of photoreceptor maturation, including the formation of light-responsive inner/outer segments and of synapses. A full-field electroretinography response was not detected (this measures the electrical responses of various cell types in the retina, including the photoreceptors, inner retinal cells, and the ganglion cells), but this does not necessarily imply total blindness, according to the study. By contrast, retinal ganglion cell responses to light stimuli were observed in three transplanted retinas out of seven that were measured. Thus, there was some indication of a functional integration of the transplanted tissues with the host retina, even though less successful than with mouse-derived stem cells in these mice models. “This study supports the use of these animals in preclinical studies, as well as the competency of human embryonic stem cell retina for future clinical applications in retinitis pigmentosa patients, ” the authors concluded.