Retinal degeneration leads to impaired vision and, in some cases, blindness. Findings from a study published in Stem Cell Reports may offer a new therapeutic option in the form of stem cell-derived transplantation of retinal sheets. The work comes from a team that includes collaborators from Central Institute for Experimental Animals, Animal Resources and Technical Research Center and RIKEN in Japan.
It is known that photoreceptor precursor cells derived from embryonic stem cells can be transplanted in adult mouse models of retinal degeneration that still have dysfunctional photoreceptor layers (or outer nuclear layer). In these models, the transplanted photoreceptor cells restored some vision. It has also been shown that the transplanted retinal sheets differentiated from mouse ES or iPS cells can create new synaptic connections and can partially restore vision even in models of end-stage retinal degeneration with no functioning photoreceptor layer. However, transplanting retina sheets derived from human embryonic stem cells in rodent models is challenging and often results in rejection and in the improper maturation of transplanted cells.
Thus, immunodeficient end-stage retinal degeneration mouse models without any outer nuclear layer structure have been considered for preclinical studies. In the study, titled “Establishment of Immunodeficient Retinal Degeneration Model Mice and Functional Maturation of Human ESC-Derived Retinal Sheets after Transplantation,” researchers transplanted retinal sheets derived from human embryonic stem cells into an immunodeficient mouse model.
In the resulting findings, retinal ganglion cell responses to light stimuli were observed in 3 transplanted retinas out of 7. This provides some indication of a functional integration of the transplanted tissues with the mouse host retina, even though this is less successful when compared to mouse-derived stem cells. The authors conclude, “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”.
See the press release from Kawasaki SkyFront.
Source: Kawasaki SkyFront