Generating human retinal ganglion cells from human induced pluripotent cells in feeder and feeder‐free conditions

Purpose Glaucoma, and other optic neuropathies, results in the loss of retinal ganglion cells (RGCs) and vision dysfunction. Therefore, cell replacement therapy may offer promising treatments to protect the degenerating retina and potentially restore vision function. Although significant progress has been made to generate photoreceptors from stem cells, there has been little advancement in efficiently generating RGCs. Therefore, we have been investigating the optimal conditions for differentiating RGCs from stem cells for cell replacement therapy. Methods Human induced pluripotent stem cells (iPSCs) were maintained and expanded on feeder layers using previously published conditions. During embryoid body formation, genes and proteins were tested for effects on increasing RGC differentiation efficiency. Differentiated RGCs were identified and quantified using RGC‐specific markers including Brn3. Feeder‐free conditions were examined for functional equivalence. Results iPSCs that express stem cell‐specific markers were passaged in proliferative conditions and differentiated into RGCs in vitro. Feeder‐free cell culture conditions allowed iPSC maintenance without the presence of mouse immunogenicity. iPSCs were found to respond to pro‐RGC differentiation signals in similar fashion to rodent embryonic retinal progenitors. Conclusion These findings will provide valuable insight in our understanding of RGC differentiation and will pave the way to cure retinal diseases. The transplantation of these cells in vivo will elucidate the integration potential of these cells in degenerating retina.